Oracle® Database

Testing Guide

12c Release 1 (12.1)

E55028-04

May 2015

Oracle Database Testing Guide, 12c Release 1 (12.1)

E55028-04

Copyright © 2008, 2015, Oracle and/or its affiliates. All rights reserved.

Primary Author:  Immanuel Chan

Contributing Authors:  Jim Garrison, Mike Zampiceni

Contributors:  Ashish Agrawal, Waleed Ahmed, Helen Altmar, Lance Ashdown, Pete Belknap, Supiti Buranawatanachoke, Romain Colle, Karl Dias, Kurt Engeleiter, Leonidas Galanis, Veeranjaneyulu Goli, Prabhaker Gongloor, Prakash Gupta, Shantanu Joshi, Prathiba Kalirengan, Karen McKeen, Mughees Minhas, Konstantinos Morfonios, Valarie Moore, Ravi Pattabhi, Bert Rich, Yujun Wang, Keith Wong, Qinyi Wu, Khaled Yagoub, Hailing Yu

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Contents

Preface

- Audience

- Documentation Accessibility

- Related Documents

- Conventions

Changes in This Release for Oracle Database Testing Guide

- Changes in Oracle Database 12c Release 1 (12.1)

- New Features

- Other Changes

1 Introduction to Oracle Database Testing

- SQL Performance Analyzer

- Database Replay

- Test Data Management

Part I SQL Performance Analyzer

2 Introduction to SQL Performance Analyzer

- Capturing the SQL Workload

- Setting Up the Test System

- Creating a SQL Performance Analyzer Task

- Measuring the Pre-Change SQL Performance

- Making a System Change

- Measuring the Post-Change SQL Performance

- Comparing Performance Measurements

- Fixing Regressed SQL Statements

3 Creating an Analysis Task

- Creating an Analysis Task Using Enterprise Manager

- Using the Parameter Change Workflow

- Using the Optimizer Statistics Workflow

- Using the Exadata Simulation Workflow

- Using the Guided Workflow

- Creating an Analysis Task Using APIs

- Configuring an Analysis Task Using APIs

- Configuring the Execution Plan Comparison Method of an Analysis Task Using APIs

- Configuring an Analysis Task for Exadata Simulation Using APIs

- Remapping Multitenant Container Database Identifiers in an Analysis Task Using APIs

4 Creating a Pre-Change SQL Trial

- Creating a Pre-Change SQL Trial Using Enterprise Manager

- Creating a Pre-Change SQL Trial Using APIs

5 Creating a Post-Change SQL Trial

- Creating a Post-Change SQL Trial Using Oracle Enterprise Manager

- Creating a Post-Change SQL Trial Using APIs

6 Comparing SQL Trials

- Comparing SQL Trials Using Oracle Enterprise Manager

- Analyzing SQL Performance Using Oracle Enterprise Manager

- Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager

- Tuning Regressed SQL Statements Using Oracle Enterprise Manager

- Comparing SQL Trials Using APIs

- Analyzing SQL Performance Using APIs

- Reviewing the SQL Performance Analyzer Report in Command-Line

- Comparing SQL Tuning Sets Using APIs

- Tuning Regressed SQL Statements Using APIs

- Tuning Regressed SQL Statements From a Remote SQL Trial Using APIs

- Creating SQL Plan Baselines Using APIs

- Using SQL Performance Analyzer Views

7 Using SPA Quick Check

- About Configuring SPA Quick Check

- Specifying Default Values for SPA Quick Check

- Validating the Impact of an Initialization Parameter Change

- Validating the Impact of Pending Optimizer Statistics

- Validating the Impact of Implementing Key SQL Profiles

- Validating Statistics Findings from Automatic SQL Tuning Advisor

8 Testing a Database Upgrade

- Upgrading from Oracle9i Database and Oracle Database 10g Release 1

- Enabling SQL Trace on the Production System

- Creating a Mapping Table

- Building a SQL Tuning Set

- Testing Database Upgrades from Oracle9i Database and Oracle Database 10g Release 1

- Upgrading from Oracle Database 10g Release 2 and Newer Releases

- Testing Database Upgrades from Oracle Database 10g Release 2 and Newer Releases

- Tuning Regressed SQL Statements After Testing a Database Upgrade

Part II Database Replay

9 Introduction to Database Replay

- Workload Capture

- Workload Preprocessing

- Workload Replay

- Analysis and Reporting

10 Capturing a Database Workload

- Prerequisites for Capturing a Database Workload

- Setting Up the Capture Directory

- Workload Capture Options

- Restarting the Database

- Using Filters with Workload Capture

- Workload Capture Restrictions

- Enabling and Disabling the Workload Capture Feature

- Enterprise Manager Privileges and Roles

- Database Replay Viewer Role

- Database Replay Operator Role

- Capturing a Database Workload Using Enterprise Manager

- Capturing Workloads from Multiple Databases Concurrently

- Monitoring a Workload Capture Using Enterprise Manager

- Monitoring an Active Workload Capture

- Stopping an Active Workload Capture

- Viewing a Completed Workload Capture

- Importing a Workload External to Enterprise Manager

- Creating Subsets from an Existing Workload

- Copying or Moving a Workload to a New Location

- Capturing a Database Workload Using APIs

- Defining Workload Capture Filters

- Starting a Workload Capture

- Stopping a Workload Capture

- Exporting AWR Data for Workload Capture

- Importing AWR Data for Workload Capture

- Monitoring Workload Capture Using Views

11 Preprocessing a Database Workload

- Preparing a Single Database Workload Using Enterprise Manager

- Creating a Database Replay Task

- Creating a Replay from a Replay Task

- Preparing the Test Database

- Preprocessing the Workload and Deploying the Replay Clients

- Preprocessing a Database Workload Using APIs

- Running the Workload Analyzer Command-Line Interface

12 Replaying a Database Workload

- Steps for Replaying a Database Workload

- Setting Up the Replay Directory

- Restoring the Database

- Resolving References to External Systems

- Connection Remapping

- User Remapping

- Specifying Replay Options

- Using Filters with Workload Replay

- Setting Up Replay Clients

- Replaying a Database Workload Using Enterprise Manager

- Setting Up the Replay Schedule and Parameters Using Enterprise Manager

- Monitoring Workload Replay Using Enterprise Manager

- Monitoring an Active Workload Replay

- Viewing a Completed Workload Replay

- Importing a Replay External to Enterprise Manager

- Replaying a Database Workload Using APIs

- Initializing Replay Data

- Remapping Connections

- Remapping Users

- Setting Workload Replay Options

- Defining Workload Replay Filters and Replay Filter Sets

- Setting the Replay Timeout Action

- Starting a Workload Replay

- Pausing a Workload Replay

- Resuming a Workload Replay

- Cancelling a Workload Replay

- Retrieving Information About Workload Replays

- Loading Divergence Data for Workload Replay

- Deleting Information About Workload Replays

- Exporting AWR Data for Workload Replay

- Importing AWR Data for Workload Replay

- Monitoring Workload Replay Using APIs

- Retrieving Information About Diverged Calls

- Monitoring Workload Replay Using Views

13 Analyzing Captured and Replayed Workloads

- Using Workload Capture Reports

- Accessing Workload Capture Reports Using Enterprise Manager

- Generating Workload Capture Reports Using APIs

- Reviewing Workload Capture Reports

- Using Workload Replay Reports

- Accessing Workload Replay Reports Using Enterprise Manager

- Generating Workload Replay Reports Using APIs

- Reviewing Workload Replay Reports

- Using Replay Compare Period Reports

- Generating Replay Compare Period Reports Using APIs

- Reviewing Replay Compare Period Reports

- Using SQL Performance Analyzer Reports

- Generating SQL Performance Analyzer Reports Using APIs

14 Using Workload Intelligence

- Overview of Workload Intelligence

- About Workload Intelligence

- Use Case for Workload Intelligence

- Requirements for Using Workload Intelligence

- Analyzing Captured Workloads Using Workload Intelligence

- Creating a Database User for Workload Intelligence

- Creating a Workload Intelligence Job

- Generating a Workload Model

- Identifying Patterns in a Workload

- Generating a Workload Intelligence Report

- Example: Workload Intelligence Results

15 Using Consolidated Database Replay

- Use Cases for Consolidated Database Replay

- Database Consolidation Using Pluggable Databases

- Stress Testing

- Scale-Up Testing

- Steps for Using Consolidated Database Replay

- Capturing Database Workloads for Consolidated Database Replay

- Setting Up the Test System for Consolidated Database Replay

- Preprocessing Database Workloads for Consolidated Database Replay

- Replaying Database Workloads for Consolidated Database Replay

- Reporting and Analysis for Consolidated Database Replay

- Using Consolidated Database Replay with Enterprise Manager

- Using Consolidated Database Replay with APIs

- Generating Capture Subsets Using APIs

- Setting the Consolidated Replay Directory Using APIs

- Defining Replay Schedules Using APIs

- Running Consolidated Database Replay Using APIs

- About Query-Only Database Replay

- Use Cases for Query-Only Database Replay

- Performing a Query-Only Database Replay

- Example: Replaying a Consolidated Workload with APIs

16 Using Workload Scale-Up

- Overview of Workload Scale-Up

- About Time Shifting

- About Workload Folding

- About Schema Remapping

- Using Time Shifting

- Using Workload Folding

- Using Schema Remapping

Part III Test Data Management

17 Application Data Models

- Creating an Application Data Model

- Managing Sensitive Column Types

- Associating a Database to an Application Data Model

- Importing and Exporting an Application Data Model

- Importing an ADM

- Exporting an ADM

- Verifying or Upgrading a Source Database

- Using Self Update to Download the Latest Data Masking and Test Data Management Templates

- Test Data Management and Access Rights

- Granting Privileges on an Application Data Model

18 Data Subsetting

- Creating a Data Subset Definition

- Generating a Subset Script

- Saving a Subset Script

- Importing and Exporting Subset Templates and Dumps

- Importing a Subset Definition

- Exporting a Subset Definition

- Creating a Subset Version of a Target Database

- Synchronizing a Subset Definition with an Application Data Model

- Granting Privileges on a Subset Definition

- About Inline Masking and Subsetting

- Inline Masking and Subsetting Scenarios

19 Masking Sensitive Data

- Overview of Oracle Data Masking

- Data Masking Concepts

- Security and Regulatory Compliance

- Roles of Data Masking Users

- Related Oracle Security Offerings

- Agent Compatibility for Data Masking

- Supported Data Types

- Format Libraries and Masking Definitions

- Recommended Data Masking Workflow

- Data Masking Task Sequence

- Defining Masking Formats

- Creating New Masking Formats

- Using Oracle-supplied Predefined Masking Formats

- Providing a Masking Format to Define a Column

- Deterministic Masking Using the Substitute Format

- Masking with an Application Data Model and Workloads

- Adding Columns for Masking

- Selecting Data Masking Advanced Options

- Scheduling a Script Generation Job

- Scheduling a Data Masking Job

- Estimating Space Requirements for Masking Operations

- Adding Dependent Columns

- Masking Dependent Columns for Packaged Applications

- Cloning the Production Database

- Importing a Data Masking Template

- Masking a Test System to Evaluate Performance

- Using Only Masking for Evaluation

- Using Cloning and Masking for Evaluation

- Upgrade Considerations

- Using the Shuffle Format

- Using Group Shuffle

- Using Conditional Masking

- Using Data Masking with LONG Columns

Index

Preface

This preface contains the following topics:

- Audience

- Documentation Accessibility

- Related Documents

- Conventions

Audience

This document provides information about how to assure the integrity of database changes and manage test data using Oracle Real Application Testing, Oracle Data Masking, and data subsetting. This document is intended for database administrators, application designers, and programmers who are responsible for performing real-world testing of Oracle Database.

Documentation Accessibility

For information about Oracle's commitment to accessibility, visit the Oracle Accessibility Program website at http://www.oracle.com/pls/topic/lookup?ctx=acc&id=docacc.

Access to Oracle Support

Oracle customers that have purchased support have access to electronic support through My Oracle Support. For information, visit http://www.oracle.com/pls/topic/lookup?ctx=acc&id=info or visit http://www.oracle.com/pls/topic/lookup?ctx=acc&id=trs if you are hearing impaired.

Related Documents

For more information about some of the topics discussed in this document, see the following documents in the Oracle Database Release 12.1 documentation set:

- Oracle Database 2 Day DBA

- Oracle Database 2 Day + Performance Tuning Guide

- Oracle Database Administrator's Guide

- Oracle Database Concepts

- Oracle Database Performance Tuning Guide

- Oracle Database SQL Tuning Guide

Conventions

The following text conventions are used in this document:

Convention

Meaning

boldface

Boldface type indicates graphical user interface elements associated with an action, or terms defined in text or the glossary.

italic

Italic type indicates book titles, emphasis, or placeholder variables for which you supply particular values.

monospace

Monospace type indicates commands within a paragraph, URLs, code in examples, text that appears on the screen, or text that you enter.

Changes in This Release for Oracle Database Testing Guide

This preface lists changes in Oracle Database Testing Guide.

Changes in Oracle Database 12c Release 1 (12.1)

The following are changes in Oracle Database Testing Guide for Oracle Database 12c Release 1 (12.1).

New Features

The following features are new in this release:

- SQL Performance Analyzer Quick Check (SPA Quick Check)
On some Oracle Enterprise Manager Cloud Control database management pages, SPA Quick Check can validate the impact of a system change to the database workload before you make the change.

See Using SPA Quick Check.

- SQL Performance Analyzer support for the multitenant architecture
You can use a SQL tuning set that was transported from a non-CDB to a multitenant container database (CDB) as the input source to SQL Performance Analyzer by remapping its CDB identifiers.

See Remapping Multitenant Container Database Identifiers in an Analysis Task Using APIs.

- Workload Intelligence
Workload Intelligence comprises a suite of Java programs that enable you to analyze the data stored in a captured workload.

See Using Workload Intelligence .

- Consolidated Database Replay
Consolidated Database Replay enables you to consolidate multiple workloads captured from one or multiple systems and replay them concurrently on a single test system, such as a single Oracle Exadata Machine.

See Using Consolidated Database Replay .

- Workload Scale-up
Database Replay enables you to perform scale-up testing and stress testing in various use cases and scenarios.

See Using Workload Scale-Up .

- Test data management
The test data management features enable you to manage test data by using Oracle Data Masking and data subsetting.

See Test Data Management .

Other Changes

The following are additional changes in the release:

- New book
Oracle Database Real Application Testing User's Guide is now part of Oracle Database Testing Guide.

- New part
Test Data Management is added to Oracle Database Testing Guide to describe the test data management features of Oracle Database.

1 Introduction to Oracle Database Testing

The Oracle Real Application Testing option and test data management features of Oracle Database help you to securely assure the integrity of database changes and to manage test data.

Oracle Real Application Testing option enables you to perform real-world testing of Oracle Database. By capturing production workloads and assessing the impact of system changes on these workloads before production deployment, Oracle Real Application Testing minimizes the risk of instabilities associated with system changes. SQL Performance Analyzer and Database Replay are key components of Oracle Real Application Testing. Depending on the nature and impact of the system change being tested, and on the type of system the test will be performed, you can use either or both components to perform your testing.

When performing real-world testing, there is the risk of exposing sensitive data to non-production users in a test environment. The test data management features of Oracle Database helps to minimize this risk by enabling you to perform data masking and data subsetting on the test data.

This chapter contains the following sections:

- SQL Performance Analyzer

- Database Replay

- Test Data Management

Note:

The use of SQL Performance Analyzer and Database Replay requires the Oracle Real Application Testing licensing option. For more information, see Oracle Database Licensing Information.

SQL Performance Analyzer

System changes—such as a upgrading a database or adding an index—may cause changes to execution plans of SQL statements, resulting in a significant impact on SQL performance. In some cases, the system changes may cause SQL statements to regress, resulting in performance degradation. In other cases, the system changes may improve SQL performance. Being able to accurately forecast the potential impact of system changes on SQL performance enables you to tune the system beforehand, in cases where the SQL statements regress, or to validate and measure the performance gain in cases where the performance of the SQL statements improves.

SQL Performance Analyzer automates the process of assessing the overall effect of a change on the full SQL workload by identifying performance divergence for each SQL statement. A report that shows the net impact on the workload performance due to the change is provided. For regressed SQL statements, SQL Performance Analyzer also provides appropriate execution plan details along with tuning recommendations. As a result, you can remedy any negative outcome before the end users are affected. Furthermore, you can validate—with significant time and cost savings—that the system change to the production environment will result in net improvement.

You can use the SQL Performance Analyzer to analyze the impact on SQL performance of any type of system changes, including:

- Database upgrade

- Database consolidation testing for pluggable databases (PDBs) and manual schema consolidation

- Configuration changes to the operating system or hardware

- Schema changes

- Changes to database initialization parameters

- Refreshing optimizer statistics

- Validating SQL tuning actions

See Also:

- SQL Performance Analyzer for information about using SQL Performance Analyzer

Database Replay

Before system changes are made, such as hardware and software upgrades, extensive testing is usually performed in a test environment to validate the changes. However, despite the testing, the new system often experiences unexpected behavior when it enters production because the testing was not performed using a realistic workload. The inability to simulate a realistic workload during testing is one of the biggest challenges when validating system changes.

Database Replay enables realistic testing of system changes by essentially re-creating the production workload environment on a test system. Using Database Replay, you can capture a workload on the production system and replay it on a test system with the exact timing, concurrency, and transaction characteristics of the original workload. This enables you to fully assess the impact of the change, including undesired results, new contention points, or plan regressions. Extensive analysis and reporting is provided to help identify any potential problems, such as new errors encountered and performance divergence.

Database Replay captures the workload of external database clients at the database level and has negligible performance overhead. Capturing the production workload eliminates the need to develop simulation workloads or scripts, resulting in significant cost reduction and time savings. By using Database Replay, realistic testing of complex applications that previously took months using load simulation tools can now be completed in days. This enables you to rapidly test changes and adopt new technologies with a higher degree of confidence and at lower risk.

You can use Database Replay to test any significant system changes, including:

- Database and operating system upgrades

- Database consolidation testing for PDBs and manual schema consolidation

- Authoring and experimenting with various scenarios using workload scale-up

- Configuration changes, such as conversion of a database from a single instance to an Oracle Real Application Clusters (Oracle RAC) environment

- Storage, network, and interconnect changes

- Operating system and hardware migrations

See Also:

- Database Replay for information about using Database Replay

Test Data Management

When production data is copied into a testing environment, there is the risk of breaching sensitive information to non-production users, such as application developers or external consultants. In order to perform real-world testing, these non-production users need to access some of the original data, but not all the data, especially when the information is deemed confidential.

Oracle Database offers test data management features that help reduce this risk by enabling you to:

- Store the list of applications, tables, and relationships between table columns using Application Data Modeling

- Replicate information that pertains only to a particular site using data subsetting

- Replace sensitive data from your production system with fictitious data that can be used during testing using Oracle Data Masking

See Also:

- Test Data Management for information about managing test data

Part I SQL Performance Analyzer

SQL Performance Analyzer enables you to assess the impact of system changes on the response time of SQL statements.

Part I covers SQL Performance Analyzer and contains the following chapters:

- Introduction to SQL Performance Analyzer

- Creating an Analysis Task

- Creating a Pre-Change SQL Trial

- Creating a Post-Change SQL Trial

- Comparing SQL Trials

- Using SPA Quick Check

- Testing a Database Upgrade

2 Introduction to SQL Performance Analyzer

You can run SQL Performance Analyzer on a production system or a test system that closely resembles the production system. Testing a system change on a production system will impact the system's throughput because SQL Performance Analyzer must execute the SQL statements that you are testing. Any global changes made on the system to test the performance effect may also affect other users of the system. If the system change does not impact many sessions or SQL statements, then running SQL Performance Analyzer on the production system may be acceptable. However, for systemwide changes—such as a database upgrade—using a production system is not recommended. Instead, consider running SQL Performance Analyzer on a separate test system so that you can test the effects of the system change without affecting the production system. Using a test system also ensures that other workloads running on the production system will not affect the analysis performed by SQL Performance Analyzer. Running SQL Performance Analyzer on a test system is the recommended approach and the methodology described here. If you choose to run the SQL Performance Analyzer on the production system, then substitute the production system for the test system where applicable.

Analyzing the SQL performance effect of system changes using SQL Performance Analyzer involves the following steps, as illustrated in Figure 2-1:

Figure 2-1 SQL Performance Analyzer Workflow

1. Capture the SQL workload that you intend to analyze and store it in a SQL tuning set, as described in "Capturing the SQL Workload".

2. If you plan to use a test system separate from your production system, then perform the following steps:

a. Set up the test system to match the production environment as closely as possible.

b. Transport the SQL tuning set to the test system.

For more information, see "Setting Up the Test System".

3. On the test system, create a SQL Performance Analyzer task, as described in "Creating a SQL Performance Analyzer Task".

4. Build the pre-change SQL trial by test executing or generating execution plans for the SQL statements stored in the SQL tuning set, as described in "Measuring the Pre-Change SQL Performance"

5. Perform the system change, as described in "Making a System Change"

6. Build the post-change SQL trial by re-executing the SQL statements in the SQL tuning set on the post-change test system, as described in "Measuring the Post-Change SQL Performance"

7. Compare and analyze the pre-change and post-change versions of performance data, and generate a report to identify the SQL statements that have improved, remained unchanged, or regressed after the system change, as described in "Comparing Performance Measurements"

8. Tune any regressed SQL statements that are identified, as described in "Fixing Regressed SQL Statements".

9. Ensure that the performance of the tuned SQL statements is acceptable by repeating steps 6 through 8 until your performance goals are met.

For each comparison, you can use any previous SQL trial as the pre-change SQL trial and the current SQL trial as the post-change SQL trial. For example, you may want to compare the first SQL trial to the current SQL trial to assess the total change, or you can compare the most recent SQL trial to the current SQL trial to assess just the most recent change.

Note:

Oracle Enterprise Manager provides automated workflows for steps 3 through 9 to simplify this process.

Note:

Data visibility and privilege requirements may differ when using SQL Performance Analyzer with pluggable databases (PDBs). For information about how manageability features—including SQL Performance Analyzer—work in a multitenant container database (CDB), see Oracle Database Administrator's Guide.

Capturing the SQL Workload

Before running SQL Performance Analyzer, capture a set of SQL statements on the production system that represents the SQL workload which you intend to analyze.

The captured SQL statements should include the following information:

- SQL text

- Execution environment

- SQL binds, which are bind values needed to execute a SQL statement and generate accurate execution statistics

- Parsing schema under which a SQL statement can be compiled

- Compilation environment, including initialization parameters under which a SQL statement is executed

- Number of times a SQL statement was executed

Capturing a SQL workload has a negligible performance impact on your production system and should not affect throughput. A SQL workload that contains more SQL statements will better represent the state of the application or database. This will enable SQL Performance Analyzer to more accurately forecast the potential impact of system changes on the SQL workload. Therefore, you should capture as many SQL statements as possible. Ideally, you should capture all SQL statements that are either called by the application or are running on the database.

You can store captured SQL statements in a SQL tuning set and use it as an input source for SQL Performance Analyzer. A SQL tuning set is a database object that includes one or more SQL statements, along with their execution statistics and execution context. SQL statements can be loaded into a SQL tuning set from different sources, including the cursor cache, Automatic Workload Repository (AWR), SQL trace files, and existing SQL tuning sets. Capturing a SQL workload using a SQL tuning set enables you to:

- Store the SQL text and any necessary auxiliary information in a single, persistent database object

- Populate, update, delete, and select captured SQL statements in the SQL tuning set

- Load and merge content from various data sources, such as the Automatic Workload Repository (AWR) or the cursor cache

- Export the SQL tuning set from the system where the SQL workload is captured and import it into another system

- Reuse the SQL workload as an input source for other advisors, such as the SQL Tuning Advisor and the SQL Access Advisor

See Also:

- Oracle Database 2 Day + Performance Tuning Guide for information about creating SQL tuning sets using Oracle Enterprise Manager

- Oracle Database SQL Tuning Guide for information about creating SQL tuning sets using APIs

Setting Up the Test System

After you have captured the SQL workload into a SQL tuning set on the production system, you can conduct SQL Performance Analyzer analysis on the same database where the workload was captured or on a different database. Because the analysis is resource-intensive, it is recommended that you capture the workload on a production database and transport it to a separate test database where the analysis can be performed. To do so, export the SQL tuning set from the production system and import it into a separate system where the system change will be tested.

There are many ways to create a test database. For example, you can use the DUPLICATE command of Recovery Manager (RMAN), Oracle Data Pump, or transportable tablespaces. Oracle recommends using RMAN because it can create the test database from pre-existing backups or from the active production datafiles. The production and test databases can reside on the same host or on different hosts.

You should configure the test database environment to match the database environment of the production system as closely as possible. In this way, SQL Performance Analyzer can more accurately forecast the effect of the system change on SQL performance.

After the test system is properly configured, export the SQL tuning set from the production system to a staging table, then import it from the staging table into the test system.

See Also:

- Oracle Database Backup and Recovery User's Guide for information about duplicating a database with RMAN

- Oracle Database 2 Day + Performance Tuning Guide for information about transporting SQL tuning sets using Oracle Enterprise Manager

- Oracle Database SQL Tuning Guide for information about transporting SQL tuning sets using APIs

Creating a SQL Performance Analyzer Task

After the SQL workload is captured and transported to the test system, and the initial database environment is properly configured, you can run SQL Performance Analyzer to analyze the effects of a system change on SQL performance.

To run SQL Performance Analyzer, you must first create a SQL Performance Analyzer task. A task is a container that encapsulates all of the data about a complete SQL Performance Analyzer analysis. A SQL Performance Analyzer analysis comprises of at least two SQL trials and a comparison. A SQL trial encapsulates the execution performance of a SQL tuning set under specific environmental conditions. When creating a SQL Performance Analyzer task, you will need to select a SQL tuning set as its input source. When building SQL trials using the test execute or explain plan methods, the SQL tuning set will be used as the source for SQL statements. The SQL Performance Analyzer analysis will show the impact of the environmental differences between the two trials.

See Also:

- Creating an Analysis Task for information about how to create a SQL Performance Analyzer task

Measuring the Pre-Change SQL Performance

Create a pre-change SQL trial before making the system change. You can use the following methods to generate the performance data needed for a SQL trial with SQL Performance Analyzer:

- Test execute
This method test executes SQL statements through SQL Performance Analyzer. This can be done on the database running SPA Performance Analyzer or on a remote database.

- Explain plan
This method generates execution plans only for SQL statements through SQL Performance Analyzer. This can be done on the database running SPA Performance Analyzer or on a remote database. Unlike the EXPLAIN PLAN statement, SQL trials using the explain plan method take bind values into account and generate the actual execution plan.

- Convert SQL tuning set
This method converts the execution statistics and plans stored in a SQL tuning set. This is only supported for APIs.

The test execute method runs each of the SQL statements contained in the workload to completion. During execution, SQL Performance Analyzer generates execution plans and computes execution statistics for each SQL statement in the workload. Each SQL statement in the SQL tuning set is executed separately from other SQL statements, without preserving their initial order of execution or concurrency. This is done at least twice for each SQL statement, for as many times as possible until the execution times out (up to a maximum of 10 times). The first execution is used to warm the buffer cache. All subsequent executions are then used to calculate the run-time execution statistics for the SQL statement based on their averages. The actual number of times that the SQL statement is executed depends on how long it takes to execute the SQL statement. Long-running SQL statement will only be executed a second time, and the execution statistics from this execution will be used. Other (faster-running) SQL statements are executed multiple times, and their execution statistics are averaged over these executions (statistics from the first execution are not used in the calculation). By averaging statistics over multiple executions, SQL Performance Analyzer can calculate more accurate execution statistics for each SQL statement. To avoid a potential impact to the database, DDLs are not supported. By default, only the query portion of DMLs is executed. Using APIs, you can execute the full DML by using the EXECUTE_FULLDML task parameter. Parallel DMLs are not supported and the query portion is not executed unless the parallel hints are removed.

Depending on its size, executing a SQL workload can be time and resource intensive. With the explain plan method, you can choose to generate execution plans only, without collecting execution statistics. This technique shortens the time to run the trial and lessens the effect on system resources, but a comprehensive performance analysis is not possible because only the execution plans will be available during the analysis. However, unlike generating a plan with the EXPLAIN PLAN command, SQL Performance Analyzer provides bind values to the optimizer when generating execution plans, which provides a more reliable prediction of what the plan will be when the SQL statement is executed.

In both cases, you can execute the SQL workload remotely on a separate database using a database link. SQL Performance Analyzer will establish a connection to the remote database using the database link, execute the SQL statements on that database, collect the execution plans and run-time statistics for each SQL statement, and store the results in a SQL trial on the local database that can be used for later analysis. This method is useful in cases where you want to:

- Test a database upgrade

- Execute the SQL workload on a system running another version of Oracle Database

- Store the results from the SQL Performance Analyzer analysis on a separate test system

- Perform testing on multiple systems with different hardware configurations

- Use the newest features in SQL Performance Analyzer even if you are using an older version of Oracle Database on your production system

Once the SQL workload is executed, the resulting execution plans and run-time statistics are stored in a SQL trial.

You can also build a SQL trial using the execution statistics and plan stored in a SQL tuning set. While this method is only supported for APIs, it may be useful in cases where you have another method to run your workload (such as Database Replay or another application testing tool), and you do not need SQL Performance Analyzer to drive the workload on the test system. In such cases, if you capture a SQL tuning set during your test runs, you can build SQL trials from these SQL tuning sets using SQL Performance Analyzer to view a more comprehensive analysis report. Unlike a standard SQL Performance Analyzer report—which has only one execution plan in each trial and one set of execution statistics generated by executing the SQL statement with one set of binds—you can generate a report that compares SQL trials built from SQL tuning sets that show all execution plans from both trials with potentially many different sets of binds across multiple executions.

See Also:

- Creating a Pre-Change SQL Trial for information about how to measure the pre-change performance

- Testing a Database Upgrade for information about executing a SQL workload on a remote system to test a database upgrade

Making a System Change

Make the change whose effect on SQL performance you intend to measure. SQL Performance Analyzer can analyze the effect of many types of system changes. For example, you can test a database upgrade, new index creation, initialization parameter changes, or optimizer statistics refresh. If you are running SQL Performance Analyzer on the production system, then consider making a change using a private session to avoid affecting the rest of the system.

Measuring the Post-Change SQL Performance

After performing the system change, create a post-change SQL trial. It is highly recommended that you create the post-change SQL trial using the same method as the pre-change SQL trial. Once built, the post-change SQL trial represents a new set of performance data that can be used to compare to the pre-change version. The results are stored in a new, or post-change, SQL trial.

See Also:

- Creating a Post-Change SQL Trial for information about how to measure the post-change performance

Comparing Performance Measurements

SQL Performance Analyzer compares the performance of SQL statements before and after the change and produces a report identifying any changes in execution plans or performance of the SQL statements.

SQL Performance Analyzer measures the impact of system changes both on the overall execution time of the SQL workload and on the response time of every individual SQL statement in the workload. By default, SQL Performance Analyzer uses elapsed time as a metric for comparison. Alternatively, you can choose the metric for comparison from a variety of available SQL run-time statistics, including:

- CPU time

- User I/O time

- Buffer gets

- Physical I/O

- Optimizer cost

- I/O interconnect bytes

- Any combination of these metrics in the form of an expression

If you chose to generate explain plans only in the SQL trials, then SQL Performance Analyzer will use the optimizer cost stored in the SQL execution plans.

Once the comparison is complete, the resulting data is generated into a SQL Performance Analyzer report that compares the pre-change and post-change SQL performance. The SQL Performance Analyzer report can be viewed as an HTML, text, or active report. Active reports provides in-depth reporting using an interactive user interface that enables you to perform detailed analysis even when disconnected from the database or Oracle Enterprise Manager.

See Also:

- Comparing SQL Trials for information about comparing performance measurements and reporting

Fixing Regressed SQL Statements

If the performance analysis performed by SQL Performance Analyzer reveals regressed SQL statements, then you can make changes to remedy the problem. For example, you can fix regressed SQL by running SQL Tuning Advisor or using SQL plan baselines. You can then repeat the process of executing the SQL statements and comparing its performance to the first execution. Repeat these steps until you are satisfied with the outcome of the analysis.

See Also:

- Comparing SQL Trials for information about fixing regressed SQL statements

3 Creating an Analysis Task

Once you have captured a SQL workload that you want to analyze into a SQL tuning set (STS), you can run SQL Performance Analyzer to analyze the effects of a system change on SQL performance. To run SQL Performance Analyzer, you must first create a SQL Performance Analyzer task. A task is a container that encapsulates all of the data about a complete SQL Performance Analyzer analysis. A SQL Performance Analyzer analysis comprises of at least two SQL trials and a comparison. A SQL trial captures the execution performance of a SQL tuning set under specific environmental conditions and can be generated automatically using SQL Performance Analyzer by one of the following methods:

- Test executing SQL statements

- Generating execution plans for SQL statements

- Referring to execution statistics and plans captured in a SQL tuning set

When creating a SQL Performance Analyzer task, you will need to select a SQL tuning set as its input source. The SQL tuning set will be used as the source for test executing or generating execution plans for SQL trials. Thus, performance differences between trials are caused by environmental differences. For more information, see "Creating a SQL Performance Analyzer Task".

This chapter described how to create a SQL Performance Analyzer task and contains the following topics:

- Creating an Analysis Task Using Enterprise Manager

- Creating an Analysis Task Using APIs

- Configuring an Analysis Task Using APIs

Note:

The primary interface for running SQL Performance Analyzer is Oracle Enterprise Manager. If for some reason Oracle Enterprise Manager is unavailable, you can run SQL Performance Analyzer using the DBMS_SQLPA PL/SQL package.

Tip:

Before running SQL Performance Analyzer, capture the SQL workload to be used in the performance analysis into a SQL tuning set on the production system, then transport it to the test system where the performance analysis will be performed, as described in "Capturing the SQL Workload".

Creating an Analysis Task Using Enterprise Manager

There are several workflows available in Oracle Enterprise Manager for creating a SQL Performance Analyzer task.

To create an analysis task using Enterprise Manager:

1. From the Performance menu, select SQL, then SQL Performance Analyzer.

If the Database Login page appears, then log in as a user with administrator privileges.

The SQL Performance Analyzer page appears.

2. Under SQL Performance Analyzer Workflows, select the workflow for creating the desired type of analysis task:

- Upgrade from 9i or 10.1

Use the upgrade from 9i or 10.1 workflow to test a database upgrade from Oracle9i Database or Oracle Database 10g Release 1 to Oracle Database 10g Release 2 and newer releases, as described in "Upgrading from Oracle9i Database and Oracle Database 10g Release 1".

- Upgrade from 10.2 or 11g
Use the upgrade from 10.2 or 11g workflow to test a database upgrade from Oracle Database 10g Release 2 or Oracle Database 11g to a later release, as described in "Upgrading from Oracle Database 10g Release 2 and Newer Releases".

- Parameter Change
Use the parameter change workflow to determine how a database initialization parameter change will affect SQL performance, as described in "Using the Parameter Change Workflow".

- Optimizer Statistics
Use the optimizer statistics workflow to analyze how changes to optimizer statistics will affect SQL performance, as described in "Using the Optimizer Statistics Workflow".

- Exadata Simulation
Use the Exadata simulation workflow to simulate how using Oracle Exadata will affect SQL performance, as described in "Using the Exadata Simulation Workflow".

- Guided workflow
Use the guided workflow to compare SQL performance for all other types of system changes, as described in "Using the Guided Workflow".

Using the Parameter Change Workflow

The parameter change workflow enables you to test the performance effect on a SQL workload when you change the value of a single environment initialization parameter. For example, you can compare SQL performance by setting the OPTIMIZER_FEATURES_ENABLE initialization parameter to 10.2.0.4 and 12.1.0.1.

After you select a SQL tuning set and a comparison metric, SQL Performance Analyzer creates a task and performs a trial with the initialization parameter set to the original value. SQL Performance Analyzer then performs a second trial with the parameter set to the changed value by issuing an ALTER SESSION statement. The impact of the change is thus contained locally to the testing session. Any regression or change in performance is reported in a system-generated SQL Performance Analyzer report.

Note:

To create an analysis task for other types of system changes, use the guided workflow instead, as described in "Using the Guided Workflow".

To use the SQL Performance Analyzer parameter change workflow:

1. On the SQL Performance Analyzer page, under SQL Performance Analyzer Workflows, click Parameter Change.
The Parameter Change page appears.

2. In the Task Name field, enter the name of the task.

3. In the SQL Tuning Set field, enter the name of the SQL tuning set that contains the SQL workload to be analyzed.
Alternatively, click the search icon to search for a SQL tuning set using the Search and Select: SQL Tuning Set window.

The selected SQL tuning set now appears in the SQL Tuning Set field.

4. In the Description field, optionally enter a description of the task.

5. In the Creation Method list, determine how the SQL trial is created and what contents are generated by performing one of the following actions:

- Select Execute SQLs.
The SQL trial generates both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements.

- Select Generate Plans.
The SQL trial invokes the optimizer to create execution plans only without actually running the SQL statements.

6. In the Per-SQL Time Limit list, determine the time limit for SQL execution during the trial by performing one of the following actions:

- Select 5 minutes.
The execution will run each SQL statement in the SQL tuning set up to 5 minutes and gather performance data.

- Select Unlimited.
The execution will run each SQL statement in the SQL tuning set to completion and gather performance data. Collecting execution statistics provides greater accuracy in the performance analysis but takes a longer time. Using this setting is not recommended because the task may be stalled by one SQL statement for a prolonged time period.

- Select Customize and enter the specified number of seconds, minutes, or hours.

7. In the Parameter Change section, complete the following steps:

a. In the Parameter Name field, enter the name of the initialization parameter whose value you want to modify, or click the Search icon to select an initialization parameter using the Search and Select: Initialization Parameters window.

b. In the Base Value field, enter the current value of the initialization parameter.

c. In the Changed Value field, enter the new value of the initialization parameter.

8. In the Comparison Metric list, select the comparison metric to use for the analysis:

- If you selected Generate Plans in Step 5, then select Optimizer Cost.

- If you selected Execute SQLs in Step 5, then select one of the following options:

- Elapsed Time

- CPU Time

- User I/O Time

- Buffer Gets

- Physical I/O

- Optimizer Cost

- I/O Interconnect Bytes

To perform the comparison analysis by using more than one comparison metric, perform separate comparison analyses by repeating this procedure using different metrics.

9. In the Schedule section:

a. In the Time Zone list, select your time zone code.

b. Select Immediately to start the task now, or Later to schedule the task to start at a time specified using the Date and Time fields.

10. Click Submit.
The SQL Performance Analyzer page appears.

In the SQL Performance Analyzer Tasks section, the status of this task is displayed. To refresh the status icon, click Refresh. After the task completes, the Status field changes to Completed.

11. In the SQL Performance Analyzer Tasks section, select the task and click the link in the Name column.
The SQL Performance Analyzer Task page appears.

This page contains the following sections:

- SQL Tuning Set
This section summarizes information about the SQL tuning set, including its name, owner, description, and the number of SQL statements it contains.

- SQL Trials
This section includes a table that lists the SQL trials used in the SQL Performance Analyzer task.

- SQL Trial Comparisons
This section contains a table that lists the results of the SQL trial comparisons

12. Click the icon in the Comparison Report column.
The SQL Performance Analyzer Task Result page appears.

13. Review the results of the performance analysis, as described in "Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager".

14. In cases when regression are identified, click the icon in the SQL Tune Report column to view a SQL tuning report.

Using the Optimizer Statistics Workflow

The optimizer statistics workflow enables you to analyze the effects of optimizer statistics changes on the performance of a SQL workload.

SQL Performance Analyzer tests the effect of new optimizer statistics by enabling pending optimizer statistics in the testing session. The first SQL trial measures the baseline SQL tuning set performance; the second SQL trial uses the pending optimizer statistics. You can then run a comparison report for the two SQL trials.

To use the optimizer statistics workflow:

1. On the SQL Performance Analyzer page, under SQL Performance Analyzer Workflows, click Optimizer Statistics.
The Optimizer Statistics page appears.

2. In the Task Name field, enter the name of the task.

3. In the SQL Tuning Set field, enter the name of the SQL tuning set that contains the SQL workload to be analyzed.
Alternatively, click the search icon to search for a SQL tuning set using the Search and Select: SQL Tuning Set window.

The selected SQL tuning set now appears in the SQL Tuning Set field.

4. In the Description field, optionally enter a description of the task.

5. In the Creation Method list, determine how the SQL trial is created and what contents are generated by performing one of the following actions:

- Select Execute SQLs.
The SQL trial generates both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements.

- Select Generate Plans.
The SQL trial invokes the optimizer to create execution plans only without actually running the SQL statements.

6. In the Per-SQL Time Limit list, determine the time limit for SQL execution during the trial by performing one of the following actions:

- Select 5 minutes.
The execution will run each SQL statement in the SQL tuning set up to 5 minutes and gather performance data.

- Select Unlimited.
The execution will run each SQL statement in the SQL tuning set to completion and gather performance data. Collecting execution statistics provides greater accuracy in the performance analysis but takes a longer time. Using this setting is not recommended because the task may be stalled by one SQL statement for a prolonged time period.

- Select Customize and enter the specified number of seconds, minutes, or hours.

7. In the Comparison Metric list, select the comparison metric to use for the comparison analysis:

- Elapsed Time

- CPU Time

- User I/O Time

- Buffer Gets

- Physical I/O

- Optimizer Cost

- I/O Interconnect Bytes

Optimizer Cost is the only comparison metric available if you chose to generate execution plans only in the SQL trials.

To perform the comparison analysis by using more than one comparison metric, perform separate comparison analyses by repeating this procedure with different metrics.

8. Ensure that pending optimizer statistics are collected, and select Pending optimizer statistics collected.

9. In the Schedule section:

a. In the Time Zone list, select your time zone code.

b. Select Immediately to start the task now, or Later to schedule the task to start at a time specified using the Date and Time fields.

10. Click Submit.
The SQL Performance Analyzer page appears.

In the SQL Performance Analyzer Tasks section, the status of this task is displayed. To refresh the status icon, click Refresh. After the task completes, the Status field changes to Completed.

11. In the SQL Performance Analyzer Tasks section, select the task and click the link in the Name column.
The SQL Performance Analyzer Task page appears.

This page contains the following sections:

- SQL Tuning Set
This section summarizes information about the SQL tuning set, including its name, owner, description, and the number of SQL statements it contains.

- SQL Trials
This section includes a table that lists the SQL trials used in the SQL Performance Analyzer task.

- SQL Trial Comparisons
This section contains a table that lists the results of the SQL trial comparisons

12. Click the icon in the Comparison Report column.
The SQL Performance Analyzer Task Result page appears.

13. Review the results of the performance analysis, as described in "Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager".
Any regressions found in performance can be fixed using SQL plan baselines and the SQL Tuning Advisor. If the pending optimizer statistics produce satisfactory performance, you can publish for use.

Using the Exadata Simulation Workflow

The Exadata simulation workflow enables you to simulate the effects of an Exadata Storage Server installation on the performance of a SQL workload.

Oracle Exadata provides extremely large I/O bandwidth coupled with a capability to offload SQL processing from the database to storage. This allows Oracle Database to significantly reduce the volume of data sent through the I/O interconnect, while at the same time offloading CPU resources to the Exadata storage cells.

SQL Performance Analyzer can analyze the effectiveness of Exadata SQL offload processing by simulating an Exadata Storage Server installation and measuring the reduction in I/O interconnect usage for the SQL workload.

Running the Exadata simulation does not require any hardware or configuration changes to your system. After you select a SQL tuning set, SQL Performance Analyzer creates a task and performs an initial trial with the Exadata Storage Server simulation disabled. SQL Performance Analyzer then performs a second trial with the Exadata Storage Server simulation enabled. SQL Performance Analyzer then compares the two trials using the I/O Interconnect Bytes comparison metric and generates a SQL Performance Analyzer report, which estimates the amount of data that would not need to be sent from the Exadata storage cells to the database if Oracle Exadata is being used. In both SQL trials, the SQL statements are executed to completion and I/O interconnect bytes measurements are taken as the actual and simulated Exadata values for the first and second trials, respectively. The measured change in I/O interconnect bytes provides a good estimate of how much filtering can be performed in the Exadata storage cells and, in turn, the amount of CPU that normally would be used to process this data, but now can be offloaded from the database.

Note:

Using the Exadata simulation will not result in any plan changes. Execution plans do not change in an Exadata Storage Server installation because the simulation focuses on measuring the improvement in I/O interconnect usage. Moreover, I/O interconnect bytes will not increase, except when data compression is used (see next note), because Oracle Exadata will only decrease the amount of data sent to the database.

Note:

Because I/O interconnect bytes is the only metric used to measure the performance change impact of using an Exadata Storage Server installation, it will not work properly if Oracle Exadata is used with data compression. Since Exadata storage cells also decompress data, the I/O interconnect bytes with Oracle Exadata (or the second SQL trial) of a SQL statement may be greater than the I/O interconnect bytes without Oracle Exadata (or the first SQL trial) where the data is compressed. This comparison will be misleading because the SQL statement will be reported as a regression; when in fact, it is not.

Note:

The Exadata simulation workflow is used to simulate an Exadata Storage Server installation on non-Exadata hardware. To test changes on Exadata hardware, use the standard SQL Performance Analyzer workflows.

Note:

The Exadata simulation is supported for DSS and data warehouse workloads only.

To use the SQL Performance Analyzer Exadata simulation workflow:

1. On the SQL Performance Analyzer page, under SQL Performance Analyzer Workflows, click Exadata Simulation.
The Exadata Simulation page appears.

2. In the Task Name field, enter the name of the task.

3. In the SQL Tuning Set field, enter the name of the SQL tuning set that contains the SQL workload to be analyzed.
Alternatively, click the search icon to search for a SQL tuning set using the Search and Select: SQL Tuning Set window.

The selected SQL tuning set now appears in the SQL Tuning Set field.

4. In the Description field, optionally enter a description of the task.

5. In the Per-SQL Time Limit list, determine the time limit for SQL execution during the trial by performing one of the following actions:

- Select 5 minutes.
The execution will run each SQL statement in the SQL tuning set up to 5 minutes and gather performance data.

- Select Unlimited.
The execution will run each SQL statement in the SQL tuning set to completion and gather performance data. Collecting execution statistics provides greater accuracy in the performance analysis but takes a longer time. Using this setting is not recommended because the task may be stalled by one SQL statement for a prolonged time period.

- Select Customize and enter the specified number of seconds, minutes, or hours.

6. In the Schedule section:

a. In the Time Zone list, select your time zone code.

b. Select Immediately to start the task now, or Later to schedule the task to start at a time specified using the Date and Time fields.

7. Click Submit.
The SQL Performance Analyzer page appears.

In the SQL Performance Analyzer Tasks section, the status of this task is displayed. To refresh the status icon, click Refresh. After the task completes, the Status field changes to Completed.

8. In the SQL Performance Analyzer Tasks section, select the task and click the link in the Name column.
The SQL Performance Analyzer Task page appears.

This page contains the following sections:

- SQL Tuning Set
This section summarizes information about the SQL tuning set, including its name, owner, description, and the number of SQL statements it contains.

- SQL Trials
This section includes a table that lists the SQL trials used in the SQL Performance Analyzer task.

- SQL Trial Comparisons
This section contains a table that lists the results of the SQL trial comparisons

9. Click the icon in the Comparison Report column.
The SQL Performance Analyzer Task Result page appears.

10. Review the results of the performance analysis, as described in "Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager".
Any SQL performance improvement with the Exadata simulation between the first and second trials is captured in the report. In general, you can expect a greater impact if the SQL workload contains queries that scan a large number of rows or a small subset of table columns. Conversely, a SQL workload that queries indexed tables or tables with fewer rows will result in a lesser impact from the Exadata simulation.

Using the Guided Workflow

The guided workflow enables you to test the performance effect of any types of system changes on a SQL workload, as listed in "SQL Performance Analyzer".

Note:

To create an analysis task to test database initialization parameter changes, use the simplified parameter change workflow instead, as described in "Using the Parameter Change Workflow".

To use the SQL Performance Analyzer task guided workflow:

1. On the SQL Performance Analyzer page, under SQL Performance Analyzer Workflows, click Guided Workflow.

The Guided Workflow page appears.

The guided workflow enables you to test the performance effect on a SQL workload when you perform any type of system changes, as described in "SQL Performance Analyzer".

This page lists the required steps in the SQL Performance Analyzer task in sequential order. Each step must be completed in the order displayed before the next step can begin.

2. On the Guided Workflow page, click the Execute icon for the Step 1: Create SQL Performance Analyzer Task based on SQL Tuning Set.

The Create SQL Performance Analyzer Task page appears.

3. In the Name field, enter the name of the task.

4. In the Description field, optionally enter a description of the task.

5. Under SQL Tuning Set, in the Name field, enter the name the SQL tuning set that contains the SQL workload to be analyzed.

Alternatively, click the search icon to select a SQL tuning set from the Search and Select: SQL Tuning Set window.

6. Click Create.

The Guided Workflow page appears.

The Status icon of this step has changed to a check mark and the Execute icon for the next step is now enabled.

7. Once the analysis task is created, you can build the pre-change performance data by executing the SQL statements stored in the SQL tuning set, as described in Creating a Pre-Change SQL Trial .

Creating an Analysis Task Using APIs

This section describes how to create a SQL Performance Analyzer task by using the DBMS_SQLPA.CREATE_ANALYSIS_TASK function. A task is a database container for SQL Performance Analyzer execution inputs and results.

Tip:

Before proceeding, capture the SQL workload to be used in the performance analysis into a SQL tuning set on the production system, then transport it to the test system where the performance analysis will be performed, as described in "Capturing the SQL Workload".

To create an analysis task:

- Call the CREATE_ANALYSIS_TASK function using the following parameters:

- Set task_name to specify an optional name for the SQL Performance Analyzer task.

- Set sqlset_name to the name of the SQL tuning set.

- Set sqlset_owner to the owner of the SQL tuning set. The default is the current schema owner.

- Set basic_filter to the SQL predicate used to filter the SQL from the SQL tuning set.

- Set order_by to specify the order in which the SQL statements will be executed.
You can use this parameter to ensure that the more important SQL statements will be processed and not skipped if the time limit is reached.

- Set top_sql to consider only the top number of SQL statements after filtering and ranking.

The following example illustrates a function call:

VARIABLE t_name VARCHAR2(100);
EXEC :t_name := DBMS_SQLPA.CREATE_ANALYSIS_TASK(sqlset_name => 'my_sts', -
task_name => 'my_spa_task');

Once the analysis task is created, you can build the pre-change performance data by executing the SQL statements stored in the SQL tuning set, as described in Creating a Pre-Change SQL Trial .

See Also:

- Oracle Database PL/SQL Packages and Types Reference to learn more about the DBMS_SQLPA.CREATE_ANALYSIS_TASK function

Configuring an Analysis Task Using APIs

This section describes how to configure a SQL Performance Analyzer task once it has been created. You can configure an analysis task by setting its parameters using the DBMS_SQLPA.SET_ANALYSIS_TASK_PARAMETER procedure.

This section contains the following topics:

- Configuring the Execution Plan Comparison Method of an Analysis Task Using APIs

- Configuring an Analysis Task for Exadata Simulation Using APIs

- Remapping Multitenant Container Database Identifiers in an Analysis Task Using APIs

Configuring the Execution Plan Comparison Method of an Analysis Task Using APIs

You can configure the comparison method that determines when a SQL Performance Analyzer task performs line-by-line comparison of execution plans. By default, a SQL Performance Analyzer task performs line-by-line comparison of execution plans only if the plan hash value is unknown.

To configure the execution plan comparison method of an analysis task:

- Use the SET_ANALYSIS_TASK_PARAMETER procedure to set the value of the PLAN_LINES_COMPARISON parameter.
Table 3-1 lists the valid values for the PLAN_LINES_COMPARISON parameter.

Table 3-1 SQL Performance Analyzer Task Execution Plan Methods

Method

Description

ALWAYS

The analysis task always performs a line-by-line comparison of execution plans.

AUTO

The analysis task performs a line-by-line comparison of execution plans only if the computation of the plan hash value for the first SQL trial has changed or the second SQL trial is unavailable.

NONE

The analysis task performs a line-by-line comparison of execution plans only if the plan hash value is unknown. This is the default value.

The following example shows how to set the execution plan method for an analysis task to AUTO:

EXEC DBMS_SQLPA.SET_ANALYSIS_TASK_PARAMETER(task_name => 'my_spa_task', -
parameter => 'PLAN_LINES_COMPARISON', -
value => 'AUTO');

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_SQLPA.SET_ANALYSIS_TASK_PARAMETER procedure

Configuring an Analysis Task for Exadata Simulation Using APIs

You can configure a SQL Performance Analyzer to run the Oracle Exadata simulation. For information about how SQL Performance Analyzer simulates the effects of an Exadata Storage Server installation on the performance of a SQL workload, see "Using the Exadata Simulation Workflow".

To enable Exadata simulation for an analysis task:

- Call the SET_ANALYSIS_TASK_PARAMETER procedure before creating the post-change SQL trial, as shown in the following example:

EXEC DBMS_SQLPA.SET_ANALYSIS_TASK_PARAMETER(task_name => 'my_spa_task', -
parameter => 'CELL_SIMULATION_ENABLED', -
value => 'TRUE');

This will enable Exadata simulation when you create the post-change SQL trial, which can then be compared to the pre-change SQL trial that was created with Exadata simulation disabled.

Alternatively, you can run the Exadata simulation using the tcellsim.sql script.

To run the Exadata simulation using tcellsim.sql:

1. At the SQL prompt, enter:

@$ORACLE_HOME/rdbms/admin/tcellsim.sql

2. Enter the name and owner of the SQL tuning set to use:

Enter value for sts_name: MY_STS
Enter value for sts_owner: IMMCHAN

The script then runs the following four steps automatically:

- Creates a SQL Performance Analyzer task

- Test executes SQL statements with Exadata simulation disabled

- Test executes SQL statements with Exadata simulation enabled

- Compares performance and generates analysis report

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_SQLPA.SET_ANALYSIS_TASK_PARAMETER procedure

Remapping Multitenant Container Database Identifiers in an Analysis Task Using APIs

You can store captured SQL statements in a SQL tuning set, and use it as an input source when creating a SQL Performance Analyzer task. SQL Performance Analyzer then uses the SQL tuning set as the source for test executing or generating execution plans for SQL trials.

If you use a SQL tuning set that was transported from a non-CDB to a multitenant container database (CDB) as the input source, the CDB identifiers of the SQL statements in the SQL tuning set must be remapped to make the STS usable in the CDB. Remapping CDB identifiers associates each SQL statement in the SQL tuning set with a CDB identifier that can be remapped to the corresponding pluggable databases (PDBs) within the CDB.

Typically, CDB identifiers should be remapped when the SQL tuning set is transported from a non-CDB to a CDB. In this case, you can simply use the SQL tuning set as an input source for SQL Performance Analyzer. However, if you are using a SQL tuning set whose CDB identifiers have not been remapped, you can specify the remapping as a SQL Performance Analyzer task property.

To remap CDB identifiers for an analysis task:

- Use the SET_ANALYSIS_TASK_PARAMETER procedure, as shown in the following example:

EXEC DBMS_SQLPA.SET_ANALYSIS_TASK_PARAMETER(task_name => 'non_cdb_spa1', -
parameter => 'CON_DBID_MAPPING', -
value => '1234:5678,1357:2468');

In this example, the CDB identifiers 1234 and 1357 are remapped to 5678 and 2468, respectively.

After the CDB identifiers are remapped, SQL Performance Analyzer uses the new CDB identifier when it finds a match for the old CDB identifier, and executes the SQL statements in the appropriate PDB within the CDB.

See Also:

- Oracle Database SQL Tuning Guide for information about transporting SQL tuning sets

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_SQLPA.SET_ANALYSIS_TASK_PARAMETER procedure

4 Creating a Pre-Change SQL Trial

After creating a SQL Performance Analyzer task and selecting a SQL tuning set as the input source, you need to establish the initial environment on the test system. Establishing the database environment on the test system involves manually making any necessary environmental changes that affect SQL optimization and performance. These changes may include changing initialization parameters, gathering or setting optimizer statistics, and creating indexes. It is recommended that you build a test system that is as similar to the production system as possible. The dedicated workflows in Enterprise Manager simplifies this process by creating both SQL trials automatically and performing the change restricted to the testing session. For information about setting up the database environment, see "Setting Up the Test System".

Note:

You can optionally run SQL trials on a remote system by providing access to a public database link. When conducting remote SQL trials, the database version of the remote database where the SQL statements are executed must be less than or equal to the database version of the database to which it connects. Starting with Oracle Database release 11.2.0.2, the remote database can be a read-only database, such as an Oracle Active Data Guard instance.

Once the environment on the test system is properly configured, you can build the pre-change version of performance data before performing the system change. You can build SQL trials using SQL Performance Analyzer by using one of the following methods:

- Executing the SQL statements in the workload

- Generating execution plans for the SQL statements in the workload

- Loading performance data and execution plans from a SQL tuning set (APIs only)

For more information, see "Measuring the Pre-Change SQL Performance"

This chapter described how to create the pre-change SQL trial and contains the following topics:

- Creating a Pre-Change SQL Trial Using Enterprise Manager

- Creating a Pre-Change SQL Trial Using APIs

Note:

The primary interface for creating a pre-change SQL trial is Oracle Enterprise Manager. If for some reason Oracle Enterprise Manager is unavailable, you can create a pre-change SQL trial using the DBMS_SQLPA PL/SQL package.

Tip:

Before creating a pre-change SQL trial, you need to create a SQL Performance Analyzer task, as described in Creating an Analysis Task .

Creating a Pre-Change SQL Trial Using Enterprise Manager

This section describes how to collect the pre-change SQL performance data using Oracle Enterprise Manager.

To create a pre-change SQL trial using Enterprise Manager:

1. On the Guided Workflow page, click the Execute icon for the Create SQL Trial in Initial Environment step.
The Create SQL Trial page appears. A summary of the selected SQL tuning set containing the SQL workload is displayed.

2. In the SQL Trial Name field, enter the name of the SQL trial.

3. In the SQL Trial Description field, enter a description of the SQL trial.

4. In the Creation Method list, determine how the SQL trial is created and what contents are generated by performing one of the following actions:

- Select Execute SQLs Locally.
The SQL trial generates both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements locally on the test system.

- Select Execute SQLs Remotely.
The SQL trial generates both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements remotely on another test system over a public database link.

- Select Generate Plans Locally.
The SQL trial invokes the optimizer to create execution plans locally on the test system, after taking bind values and optimizer configuration into account, without actually running the SQL statements.

- Select Generate Plans Remotely.
The SQL trial invokes the optimizer to create execution plans remotely on another test system, after taking bind values and optimizer configuration into account, over a public database link without actually running the SQL statements.

- Select Build From SQL Tuning Set.
The SQL trial copies the execution plans and statistics from the SQL tuning set directly into the trial.

For more information about the different methods, see "Measuring the Pre-Change SQL Performance".

5. In the Per-SQL Time Limit list, determine the time limit for SQL execution during the trial by performing one of the following actions:

- Select 5 minutes.
The execution will run each SQL statement in the SQL tuning set up to 5 minutes and gather performance data.

- Select Unlimited.
The execution will run each SQL statement in the SQL tuning set to completion and gather performance data. Collecting execution statistics provides greater accuracy in the performance analysis but takes a longer time. Using this setting is not recommended because the task may be stalled by one SQL statement for a prolonged period.

- Select Customize and enter the specified number of seconds, minutes, or hours.

6. Ensure that the database environment on the test system matches the production environment as closely as possible, and select Trial environment established.

7. In the Schedule section:

a. In the Time Zone list, select your time zone code.

b. Select Immediately to start the task now, or Later to schedule the task to start at a time specified using the Date and Time fields.

8. Click Submit.
The Guided Workflow page appears when the execution begins.

The status icon of this step changes to a clock while the execution is in progress. To refresh the status icon, click Refresh. Depending on the options selected and the size of the SQL workload, the execution may take a long time to complete. After the execution is completed, the Status icon will change to a check mark and the Execute icon for the next step is enabled.

9. Once the pre-change performance data is built, you can make the system change and build the post-change performance data by re-executing the SQL statements in the SQL tuning set on the post-change test system, as described in Creating a Post-Change SQL Trial .

Creating a Pre-Change SQL Trial Using APIs

This section describes how to build the pre-change performance data by using the DBMS_SQLPA package.

To create a pre-change SQL trial:

- Call the EXECUTE_ANALYSIS_TASK procedure using the following parameters:

- Set the task_name parameter to the name of the SQL Performance Analyzer task that you want to execute.

- Set the execution_type parameter in one of the following ways:

- Set to EXPLAIN PLAN to generate execution plans for all SQL statements in the SQL tuning set without executing them.

- Set to TEST EXECUTE (recommended) to execute all statements in the SQL tuning set and generate their execution plans and statistics. When TEST EXECUTE is specified, the procedure generates execution plans and execution statistics. The execution statistics enable SQL Performance Analyzer to identify SQL statements that have improved or regressed. Collecting execution statistics in addition to generating execution plans provides greater accuracy in the performance analysis, but takes longer.

- Set to CONVERT SQLSET to refer to a SQL tuning set for the execution statistics and plans for the SQL trial. Values for the execution parameters SQLSET_NAME and SQLSET_OWNER should also be specified.

- Specify a name to identify the execution using the execution_name parameter. If not specified, then SQL Performance Analyzer automatically generates a name for the task execution.

- Specify execution parameters using the execution_params parameters. The execution_params parameters are specified as (name, value) pairs for the specified execution. For example, you can set the following execution parameters:

- The time_limit parameter specifies the global time limit to process all SQL statements in a SQL tuning set before timing out.

- The local_time_limit parameter specifies the time limit to process each SQL statement in a SQL tuning set before timing out.

- To perform a remote test execute, set the DATABASE_LINK task parameter to the global name of a public database link connecting to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the test system.

- To fully execute DML statements—including acquiring row locks and modifying row—set the EXECUTE_FULLDML parameter to TRUE. SQL Performance Analyzer will issue a rollback after executing the DML statements to prevent persistent changes from being made. The default value for this parameter is FALSE, which executes only the query portion of the DML statement without modifying the data.

- To restore the relevant captured init.ora settings during a test execute, set the APPLY_CAPTURED_COMPILENV parameter to TRUE. This is not the default behavior because typically you are running SQL trials to test changes when changing the environment. However, this method may be used in cases when the init.ora settings are not being changed (such as creating an index). This method is not supported for remote SQL trials.

The following example illustrates a function call made before a system change:

EXEC DBMS_SQLPA.EXECUTE_ANALYSIS_TASK(task_name => 'my_spa_task', -
execution_type => 'TEST EXECUTE', -
execution_name => 'my_exec_BEFORE_change');

Once the pre-change performance data is built, you can make the system change and build the post-change performance data by re-executing the SQL statements in the SQL tuning set on the post-change test system, as described in Creating a Post-Change SQL Trial .

See Also:

- Oracle Database PL/SQL Packages and Types Reference to learn about the DBMS_SQLPA.EXECUTE_ANALYSIS_TASK function

5 Creating a Post-Change SQL Trial

After computing the pre-change SQL performance data, you can perform the system change on the test system. Before making the system change, ensure that you have executed the SQL workload in the initial environment to generate the pre-change performance data. For example, if you are testing how changing a database initialization parameter will affect SQL performance, execute the SQL workload once before changing the database initialization parameter to a new value. Depending on the type of change you are making, it may be necessary to reconfigure the environment on the test system to match the new environment for which you want to perform SQL performance analysis. For more information, see "Making a System Change".

Note:

You can optionally run SQL trials on a remote system by providing access to a public database link. When conducting remote SQL trials, the database version of the remote database where the SQL statements are executed must be less than or equal to the database version of the database to which it connects. Starting with Oracle Database release 11.2.0.2, the remote database can be a read-only database, such as an Oracle Active Data Guard instance.

"SQL Performance Analyzer" lists examples of possible system changes that can be analyzed using SQL Performance Analyzer. For example, you may want to determine how a database initialization parameter change or database upgrade will affect SQL performance. You may also decide to change the system based on recommendations from an advisor such as Automatic Database Diagnostic Monitor (ADDM), SQL Tuning Advisor, or SQL Access Advisor.

After you have made the system change, you can build the post-change version of performance data by executing the SQL workload again. SQL Performance Analyzer will store the results from executing the SQL statements in a post-change SQL trial. For more information, see "Measuring the Post-Change SQL Performance".

This section described how to create the post-change SQL trial and contains the following topics:

- Creating a Post-Change SQL Trial Using Oracle Enterprise Manager

- Creating a Post-Change SQL Trial Using APIs

Note:

The primary interface for creating a post-change SQL trial is Oracle Enterprise Manager. If for some reason Oracle Enterprise Manager is unavailable, you can create a post-change SQL trial using the DBMS_SQLPA PL/SQL package.

Tip:

Before making the system change creating a post-change SQL trial, you need to create a pre-change SQL trial, as described in Creating a Pre-Change SQL Trial .

Creating a Post-Change SQL Trial Using Oracle Enterprise Manager

This section describes how to collect the post-change SQL performance data using Oracle Enterprise Manager.

To create a post-change SQL trial using Enterprise Manager:

1. On the Guided Workflow page, click the Execute icon for the Create SQL Trial in Changed Environment step.
The Create SQL Trial page appears.

2. In the SQL Trial Name field, enter the name of the SQL trial.

3. In the SQL Trial Description field, enter a description of the SQL trial.

4. In the Creation Method list, determine how the SQL trial is created and what contents are generated by performing one of the following actions:

- Select Execute SQLs Locally.
The SQL trial generates both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements locally on the test system.

- Select Execute SQLs Remotely.
The SQL trial generates both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements remotely on another test system over a public database link.

- Select Generate Plans Locally.
The SQL trial invokes the optimizer to create execution plans locally on the test system without actually running the SQL statements.

- Select Generate Plans Remotely.
The SQL trial invokes the optimizer to create execution plans remotely on another test system over a public database link without actually running the SQL statements.

For each of these creation methods, the application schema and data should already exist on the local or remote test system.

5. In the Per-SQL Time Limit list, determine the time limit for SQL execution during the trial by performing one of the following actions:

- Select 5 minutes.
The execution will run each SQL statement in the SQL tuning set up to 5 minutes and gather performance data.

- Select Unlimited.
The execution will run each SQL statement in the SQL tuning set to completion and gather performance data. Collecting execution statistics provides greater accuracy in the performance analysis but takes a longer time. Using this setting is not recommended because the task may be stalled by one SQL statement for a prolonged time period.

- Select Customize and enter the specified number of seconds, minutes, or hours.

6. Ensure that the system change you are testing has been performed on the test system, and select Trial environment established.

7. In the Schedule section:

a. In the Time Zone list, select your time zone code.

b. Select Immediately to start the task now, or Later to schedule the task to start at a time specified using the Date and Time fields.

8. Click Submit.
The Guided Workflow page appears when the execution begins.

The status icon of this step changes to a clock while the execution is in progress. To refresh the status icon, click Refresh. Depending on the options selected and the size of the SQL workload, the execution may take a long time to complete. After the execution is completed, the Status icon will change to a check mark and the Execute icon for the next step is enabled.

9. Once the post-change performance data is built, you can compare the pre-change SQL trial to the post-change SQL trial by running a comparison analysis, as described in Comparing SQL Trials .

Creating a Post-Change SQL Trial Using APIs

This section describes how to collect the post-change SQL performance data using the DBMS_SQLPA package.

Note:

If you are running the SQL statements remotely on another test system over a database link, the remote user calling this procedure needs to have the EXECUTE privilege for the DBMS_SQLPA package.

To create a post-change SQL trial:

- Call the EXECUTE_ANALYSIS_TASK procedure using the parameters described in "Creating a Pre-Change SQL Trial Using APIs".
Be sure to specify a different value for the execution_name parameter. It is also highly recommended that you create the post-change SQL trial using the same method as the pre-change SQL trial by using the same value for the execution_type parameter.

Note:

If you want to run an Oracle Exadata simulation, you should first set the CELL_SIMULATION_ENABLED task parameter to TRUE. For more information, see "Configuring an Analysis Task for Exadata Simulation Using APIs".

The following example illustrates a function call made after a system change:

EXEC DBMS_SQLPA.EXECUTE_ANALYSIS_TASK(task_name => 'my_spa_task', -
execution_type => 'TEST EXECUTE', -
execution_name => 'my_exec_AFTER_change');

Once the post-change performance data is built, you can compare the pre-change SQL trial to the post-change SQL trial by running a comparison analysis, as described in Comparing SQL Trials .

See Also:

- Oracle Database PL/SQL Packages and Types Reference to learn about the DBMS_SQLPA.EXECUTE_ANALYSIS_TASK function

6 Comparing SQL Trials

After the post-change SQL performance data is built, you can compare the performance data collected in the pre-change SQL trial to the post-change SQL trial by running a comparison analysis using SQL Performance Analyzer. After the comparison analysis is completed, you can generate a report to identify the SQL statements that have improved, remained unchanged, or regressed due to the system change. The SQL Performance Analyzer report calculates two chief impact measurements for the change in performance of each SQL statement:

- Impact on workload
This represents the percentage of impact that this change to the SQL statement has on the cumulative execution time of the workload, after accounting for execution frequency. For example, a change that causes a SQL statement's cumulative execution time to improve from 101 seconds to 1 second—where the rest of the workload had a total execution time of 99 seconds before the change—would have a 50% (2x) value for this measurement.

- Impact on SQL
This represents the percentage of impact that this change to the SQL statement has on the SQL statement's response time. For example, a change that causes a SQL statement's response time to improve from 10 seconds to 1 second will have a 90% (10x) value for this measurement.

For more information, see "Comparing Performance Measurements".

This chapter describes how to compare and analyze the performance data from the pre-change and post-change SQL trials and contains the following topics:

- Comparing SQL Trials Using Oracle Enterprise Manager

- Comparing SQL Trials Using APIs

Note:

The primary interface for comparing SQL trials is Oracle Enterprise Manager. If for some reason Oracle Enterprise Manager is unavailable, you can compare SQL trials using the DBMS_SQLPA PL/SQL package.

Tip:

Before comparing SQL trials, you need to create a post-change SQL trial, as described in Creating a Post-Change SQL Trial .

Comparing SQL Trials Using Oracle Enterprise Manager

Comparing SQL trials using Oracle Enterprise Manager involves the following steps:

- Analyzing SQL Performance Using Oracle Enterprise Manager

- Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager

- Tuning Regressed SQL Statements Using Oracle Enterprise Manager

Analyzing SQL Performance Using Oracle Enterprise Manager

This section describes how to analyze SQL performance before and after the system change using Oracle Enterprise Manager.

To analyze SQL performance using Enterprise Manager:

1. On the Guided Workflow page, click the Execute icon for Compare Step 2 and Step 3.
The Run SQL Trial Comparison page appears.

In this example, the SQL_TRIAL_1241213421833 and SQL_TRIAL_1241213881923 trials are selected for comparison.

2. To compare trials other than those listed by default, select the desired trials in the Trial 1 Name and Trial 2 Name lists.
Note that you cannot compare a statistical trial with a trial that tests the explain plan only.

3. In the Comparison Metric list, select the comparison metric to use for the comparison analysis:

- Elapsed Time

- CPU Time

- User I/O Time

- Buffer Gets

- Physical I/O

- Optimizer Cost

- I/O Interconnect Bytes

Optimizer Cost is the only comparison metric available if you generated execution plans only in the SQL trials.

To perform the comparison analysis by using more than one comparison metric, perform separate comparison analyses by repeating this procedure with different metrics.

4. In the Schedule section:

a. In the Time Zone list, select your time zone code.

b. Select Immediately to start the task now, or Later to schedule the task to start at a time specified using the Date and Time fields.

5. Click Submit.
The Guided Workflow page appears when the comparison analysis begins.

The status icon of this step changes to an arrow icon while the comparison analysis is in progress. To refresh the status icon, click Refresh. Depending on the amount of performance data collected from the pre-change and post-change executions, the comparison analysis may take a long time to complete. After the comparison analysis is completed, the Status icon changes to a check mark and the Execute icon for the next step is enabled.

6. Once SQL Performance Analyzer has analyzed the pre-change and post-change performance data, generate a SQL Performance Analyzer report that you can use for further analysis.
On the Guided Workflow page, click the Execute icon for View Trial Comparison Report.

The SQL Performance Analyzer Task Report page appears. Review the report, as described in "Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager".

Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager

When a SQL Performance Analyzer task is completed, the resulting data is generated into a SQL Performance Analyzer report that compares the pre-change and post-change SQL performance.

Figure 6-1 shows a sample SQL Performance Analyzer report. This sample report uses the elapsed time comparison metric to compare the pre-change and post-change executions of a SQL workload.

Figure 6-1 SQL Performance Analyzer Report

Tip:

Before you can view the SQL Performance Analyzer report, compare the pre-change version of performance data with the post-change version, as described in "Comparing SQL Trials Using Oracle Enterprise Manager"

To generate and review the SQL Performance Analyzer report:

1. From the Performance menu, select SQL, then SQL Performance Analyzer.
If the Database Login page appears, then log in as a user with administrator privileges.

The SQL Performance Analyzer page appears. A list of existing SQL Performance Analyzer tasks are displayed.

2. Under SQL Performance Analyzer Tasks, select the task for which you want to view a SQL Performance Analyzer report and click View Latest Report.
The SQL Performance Analyzer Task Report page appears.

3. Review the general information about the performance analysis, as described in "Reviewing the SQL Performance Analyzer Report: General Information".

4. Review general statistics, as described in "Reviewing the SQL Performance Analyzer Report: Global Statistics".

5. Optionally, review the detailed statistics, as described in "Reviewing the SQL Performance Analyzer Report: Global Statistics Details".

6. To generate an active report, click Save to generate and save the report, or Mail to generate and mail the report as an HTML attachment.
Active reports include information about the top SQL statements from each category (such as improved, regressed, and changed plans) with pre-change and post-change statistics, explain plans, and task summary.

For more information, see "About SQL Performance Analyzer Active Reports".

Reviewing the SQL Performance Analyzer Report: General Information

The General Information section contains basic information and metadata about the workload comparison performed by SQL Performance Analyzer.

To review general information:

1. On the SQL Performance Analyzer Task Report page, review the summary at the top of the page.

This summary includes the following information:

- The name and owner of the SQL tuning set

- The total number of SQL statements in the tuning set and the number of SQL statements that had errors, are unsupported, or timed out

- The names of the SQL trials and the comparison metric used

2. Optionally, click the link next to SQL Tuning Set Name.

The SQL Tuning Set page appears.

This page contains information—such as SQL ID and SQL text—about every SQL statement in the SQL tuning set.

3. Click the link next to SQL Statements With Errors if errors were found.

The Errors table reports all errors that occurred while executing a given SQL workload. An error may be reported at the SQL tuning set level if it is common to all SQL executions in the SQL tuning set, or at the execution level if it is specific to a SQL statement or execution plan.

4. Review the global statistics, as described in "Reviewing the SQL Performance Analyzer Report: Global Statistics".

Reviewing the SQL Performance Analyzer Report: Global Statistics

The Global Statistics section reports statistics that describe the overall performance of the entire SQL workload. This section is a very important part of the SQL Performance Analyzer analysis, because it reports on the impact of the system change on the overall performance of the SQL workload. Use the information in this section to understand the tendency of the workload performance, and determine how it will be affected by the system change.

To review global statistics:

1. Review the chart in the Projected Workload Elapsed Time subsection.

Note:

The name of the subsection may vary based on the comparison metric that is selected.

The chart shows the two trials on the x-axis and the elapsed time (in seconds) on the y-axis.

The most important statistic is the overall impact, which is given as a percentage. The overall impact is the difference between the improvement impact and the regression impact. You can click the link for any impact statistic to obtain more details, as described in "Reviewing the SQL Performance Analyzer Report: Global Statistics Details".

In this example, the improvement impact is 20%, while the regression impact is -2%, so the overall impact of the system change is an improvement of approximately 18%. This means that if all regressions are fixed in this example, the overall impact of the change will be an improvement of 20%.

Note:

The overall impact percentage may sometimes be off by 1% compared to the sum of the improvement impact and the regression impact. This discrepancy may be caused by rounding or if the SQL and workload time limits are set at 1%, which is the recommended value. This enables the analysis to focus on SQL statements with higher impact by filtering out those that have a minimal impact.

2. Review the chart in the SQL Statement Count subsection.

The x-axis of the chart shows the number of SQL statements whose performance improved, regressed, or remain unchanged after the system change. The y-axis shows the number of SQL statements. The chart also indicates whether the explain plans changed for the SQL statements.

This chart enables you to quickly weigh the relative performance of the SQL statements. You can click any bar in the chart to obtain more details about the SQL statements, as described in "Reviewing the SQL Performance Analyzer Report: Global Statistics Details". Only up to the top 100 SQL statements will be displayed, even if the actual number of SQL statements exceeds 100.

In this example, all SQL statements were unchanged after the system change.

Reviewing the SQL Performance Analyzer Report: Global Statistics Details

You can use the SQL Performance Analyzer Report to obtain detailed statistics for the SQL workload comparison. The details chart enables you to drill down into the performance of SQL statements that appears in the report. Use the information in this section to investigate why the performance of a particular SQL statement regressed.

Note:

The report displays only up to the top 100 SQL statements, even if the actual number of SQL statements exceeds 100.

To review global statistics details:

1. In the Projected Workload Elapsed Time subsection, click the impact percentage of the SQL statements for which you want to view details. To view SQL statements whose performance:

- Improved, click the percentage for Improvement Impact

- Regressed, click the percentage for Regression Impact

- Improved or regressed, click the percentage for Overall Impact

A table including the detailed statistics appears. Depending on the type of SQL statements chosen, the following columns are included:

- SQL ID
This column indicates the ID of the SQL statement.

- Net Impact on Workload (%)
This column indicates the impact of the system change relative to the performance of the SQL workload.

- Elapsed Time
This column indicates the total time (in seconds) of the SQL statement execution.

- Net Impact on SQL (%)
This column indicates the local impact of the change on the performance of a particular SQL statement.

- New Plan
This column indicates whether the SQL execution plan changed.

2. To view details about a particular SQL statement, click the SQL ID link for the SQL statement that you are interested in.

The SQL Details page appears.

You can use this page to access the SQL text and obtain low-level details about the SQL statement, such as its execution statistics and execution plan.

About SQL Performance Analyzer Active Reports

SQL Performance Analyzer active reports are HTML files that display all reporting data using a Web-hosted interactive user interface. Similar to the SQL Performance Analyzer reports available in Oracle Enterprise Manager, active reports include information about the top SQL statements from each category (such as improved, regressed, and changed plans) with pre-change and post-change statistics, explain plans, and task summary.

SQL Performance Analyzer active reports are more useful than traditional HTML or text reports because they offer a similar user interface as Oracle Enterprise Manager, yet they can be viewed even when the database is unavailable, or even after a database is dropped. Hence active reports offer the advantages of traditional reporting and dynamic Oracle Enterprise Manager analysis, but eliminates the disadvantages of both. Moreover, active reports contain more information about the comparison analysis and provide more user interactive options. It is strongly recommended that you use active reports instead of HTML or text reports.

The active report user interface components are very similar to those displayed in Oracle Enterprise Manager. For descriptions of the user interface components, see the related sections described in "Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager".

Tuning Regressed SQL Statements Using Oracle Enterprise Manager

After reviewing the SQL Performance Analyzer report, you should tune any regressed SQL statements that are identified after comparing the SQL performance. If there are large numbers of SQL statements that appear to have regressed, you should try to identify the root cause and make system-level changes to rectify the problem. In cases when only a few SQL statements have regressed, consider using one of the following tuning methods to implement a point solution for them:

- Creating SQL Plan Baselines

- Running SQL Tuning Advisor

After tuning the regressed SQL statements, you should test these changes using SQL Performance Analyzer. Run a new SQL trial on the test system, followed by a second comparison (between this new SQL trial and the first SQL trial) to validate your results. Once SQL Performance Analyzer shows that performance has stabilized, the testing is complete. Implement the fixes from this step to your production system.

Starting with Oracle Database 11g Release 1, SQL Tuning Advisor performs an alternative plan analysis when tuning a SQL statement. SQL Tuning Advisor searches the current system for previous execution plans, including the plans from the first SQL trial. If the execution plans from the first SQL trial differ from those of the second SQL trial, SQL Tuning Advisor will recommend the plans from the first SQL trial. If these execution plans produce better performance, you can create plan baselines using the plans from the first SQL trial.

Note:

SQL Performance Analyzer does not provide the option to create SQL plan baselines or run SQL Tuning Advisor directly after after completing a remote SQL trial. In such cases, you need to use APIs to manually transport the SQL tuning set and complete the appropriate procedure on the remote database.

See Also:

- Oracle Database SQL Tuning Guide for information about alternative plan analysis

Creating SQL Plan Baselines

Creating SQL plan baselines enables the optimizer to avoid performance regressions by using execution plans with known performance characteristics. If a performance regression occurs due to plan changes, a SQL plan baseline can be created and used to prevent the optimizer from picking a new, regressed execution plan.

To create SQL plan baselines:

1. On the SQL Performance Analyzer Task Result page, under Recommendations, click Create SQL Plan Baselines.
The Create SQL Plan Baselines page appears. The Regressed SQL Statements section lists the regressed SQL statements that will be associated with the new SQL plan baselines.

2. Under Job Parameters, specify the parameters for the job:

a. In the Job Name field, enter a name for the job.

b. In the Description field, optionally enter a description for the job.

3. Under Schedule, select:

- Immediately to start the job now.

- Later to schedule the job to start at a time specified using the Time Zone, Date, and Time fields.

4. Click OK.
The SQL Performance Analyzer Task Result page appears. A message is displayed to inform you that the job has been submitted successfully.

See Also:

- Oracle Database 2 Day + Performance Tuning Guide for information about creating and managing SQL plan baselines

Running SQL Tuning Advisor

The SQL Tuning Advisor performs an in-depth analysis of regressed SQL statements and attempts to fix the root cause of the problem.

To run SQL Tuning Advisor:

1. On the SQL Performance Analyzer Task Result page, under Recommendations, click Run SQL Tuning Advisor.

The Schedule SQL Tuning Task page appears.

2. In the Tuning Task Name field, enter a name for the SQL tuning task.

3. In the Tuning Task Description field, optionally enter a name for the SQL tuning task.

4. Under Schedule, select:

- Immediately to start the job now.

- Later to schedule the job to start at a time specified using the Time Zone, Date, and Time fields.

5. Click OK.

The SQL Performance Analyzer Task Result page appears. A link to the SQL tuning report appears under Recommendations.

6. To view the SQL tuning report, click the SQL Tune Report link.

The SQL Tuning Results page appears.

See Also:

- Oracle Database 2 Day + Performance Tuning Guide for information about running the SQL Tuning Advisor

Comparing SQL Trials Using APIs

Comparing SQL trials using APIs involves the following steps:

- Analyzing SQL Performance Using APIs

- Reviewing the SQL Performance Analyzer Report in Command-Line

- Comparing SQL Tuning Sets Using APIs

- Tuning Regressed SQL Statements Using APIs

- Tuning Regressed SQL Statements From a Remote SQL Trial Using APIs

- Creating SQL Plan Baselines Using APIs

- Using SQL Performance Analyzer Views

Analyzing SQL Performance Using APIs

After the post-change SQL performance data is built, you can compare the pre-change version of performance data to the post-change version. Run a comparison analysis using the DBMS_SQLPA.EXECUTE_ANALYSIS_TASK procedure or function.

To compare the pre-change and post-change SQL performance data:

1. Call the EXECUTE_ANALYSIS_TASK procedure or function using the following parameters:

- Set the task_name parameter to the name of the SQL Performance Analyzer task.

- Set the execution_type parameter to COMPARE PERFORMANCE. This setting will analyze and compare two versions of SQL performance data.

- Specify a name to identify the execution using the execution_name parameter. If not specified, it will be generated by SQL Performance Analyzer and returned by the function.

- Specify two versions of SQL performance data using the execution_params parameters. The execution_params parameters are specified as (name, value) pairs for the specified execution. Set the execution parameters that are related to comparing and analyzing SQL performance data as follows:

- Set the execution_name1 parameter to the name of the first execution (before the system change was made). This value should correspond to the value of the execution_name parameter specified in "Creating a Pre-Change SQL Trial Using APIs".

- Set the execution_name2 parameter to the name of the second execution (after the system change was made). This value should correspond to the value of the execution_name parameter specified in "Creating a Post-Change SQL Trial Using APIs" when you executed the SQL workload after the system change. If the caller does not specify the executions, then by default SQL Performance Analyzer will always compare the last two task executions.

- Set the comparison_metric parameter to specify an expression of execution statistics to use in the performance impact analysis. Possible values include the following metrics or any combination of them: elapsed_time (default), cpu_time, buffer_gets, disk_reads, direct_writes, optimizer_cost, and io_interconnect_bytes.

For other possible parameters that you can set for comparison, see the description of the DBMS_SQLPA package in Oracle Database PL/SQL Packages and Types Reference.

The following example illustrates a function call:

EXEC DBMS_SQLPA.EXECUTE_ANALYSIS_TASK(task_name => 'my_spa_task', -
execution_type => 'COMPARE PERFORMANCE', -
execution_name => 'my_exec_compare', -
execution_params => dbms_advisor.arglist(-
'comparison_metric', 'buffer_gets'));

2. Call the REPORT_ANALYSIS_TASK function using the following parameters:

- Set the task_name parameter to the name of the SQL Performance Analyzer task.

- Set the execution_name parameter to the name of the execution to use. This value should match the execution_name parameter of the execution for which you want to generate a report.
To generate a report to display the results of:

- Execution plans generated for the SQL workload, set this value to match the execution_name parameter of the desired EXPLAIN PLAN execution.

- Execution plans and execution statistics generated for the SQL workload, set this parameter to match the value of the execution_name parameter used in the desired TEST EXECUTE execution.

- A comparison analysis, set this value to match the execution_name parameter of the desired ANALYZE PERFORMANCE execution.

If unspecified, SQL Performance Analyzer generates a report for the last execution.

- Set the type parameter to specify the type of report to generate. Possible values include TEXT (default), HTML, XML, and ACTIVE.
Active reports provides in-depth reporting using an interactive user interface that enables you to perform detailed analysis even when disconnected from the database or Oracle Enterprise Manager. It is recommended that you use active reports instead of HTML or text reports when possible.

For information about active reports, see "About SQL Performance Analyzer Active Reports".

- Set the level parameter to specify the format of the recommendations. Possible values include TYPICAL (default), ALL, BASIC, CHANGED, CHANGED_PLANS, ERRORS, IMPROVED, REGRESSED, TIMEOUT, UNCHANGED, UNCHANGED_PLANS, and UNSUPPORTED.

- Set the section parameter to specify a particular section to generate in the report. Possible values include SUMMARY (default) and ALL.

- Set the top_sql parameter to specify the number of SQL statements in a SQL tuning set to generate in the report. By default, the report shows the top 100 SQL statements impacted by the system change.

To generate an active report, run the following script:

set trimspool on
set trim on
set pages 0
set linesize 1000
set long 1000000
set longchunksize 1000000
spool spa_active.html
SELECT DBMS_SQLPA.REPORT_ANALYSIS_TASK(task_name => 'my_spa_task',
type => 'active', section => 'all') FROM dual;
spool off

The following example illustrates a portion of a SQL script that you could use to create and display a comparison summary report in text format:

VAR rep   CLOB;
EXEC :rep := DBMS_SQLPA.REPORT_ANALYSIS_TASK('my_spa_task', -
'text', 'typical', 'summary');
SET LONG 100000 LONGCHUNKSIZE 100000 LINESIZE 130
PRINT :rep

3. Review the SQL Performance Analyzer report, as described in "Reviewing the SQL Performance Analyzer Report in Command-Line".

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_SQLPA.EXECUTE_ANALYSIS_TASK and DBMS_SQLPA.REPORT_ANALYSIS_TASK functions

Reviewing the SQL Performance Analyzer Report in Command-Line

The SQL Performance Analyzer report is divided into the following sections:

- General Information

- Result Summary

- Result Details

This section uses a sample report to illustrate how to review the SQL Performance Analyzer report. The sample report uses buffer_gets as the comparison metric to compare the pre-change and post-change executions of a SQL workload.

General Information

The General Information section contains basic information and metadata about the SQL Performance Analyzer task, the SQL tuning set used, and the pre-change and post-change executions. Example 6-1 shows the General Information section of a sample report.

In Example 6-1, the Task Information section indicates that the task name is my_spa_task. The Workload Information section indicates that the task compares executions of the my_sts SQL tuning set, which contains 101 SQL statements. As shown in the Execution Information section, the comparison execution is named my_exec_compare.

The Analysis Information sections shows that SQL Performance Analyzer compares two executions of the my_sts SQL tuning set, my_exec_BEFORE_change and my_exec_AFTER_change, using buffer_gets as a comparison metric.

Example 6-1 General Information

---------------------------------------------------------------------------------------------
General Information
---------------------------------------------------------------------------------------------

Task Information:                              Workload Information:
---------------------------------------------  ---------------------------------------------
Task Name    : my_spa_task                     SQL Tuning Set Name        : my_sts
Task Owner   : APPS                            SQL Tuning Set Owner       : APPS
Description  :                                 Total SQL Statement Count  : 101

Execution Information:
---------------------------------------------------------------------------------------------
Execution Name  : my_exec_compare        Started             : 05/21/2007 11:30:09
Execution Type  : ANALYZE PERFORMANCE    Last Updated        : 05/21/2007 11:30:10
Description     :                        Global Time Limit   : UNLIMITED
Scope           : COMPREHENSIVE          Per-SQL Time Limit  : UNUSED
Status          : COMPLETED              Number of Errors    : 0

Analysis Information:
---------------------------------------------------------------------------------------------
Comparison Metric: BUFFER_GETS
------------------
Workload Impact Threshold: 1%
--------------------------
SQL Impact Threshold: 1%
----------------------
Before Change Execution:                       After Change Execution:
---------------------------------------------  ---------------------------------------------
Execution Name      : my_exec_BEFORE_change    Execution Name      : my_exec_AFTER_change
Execution Type      : TEST EXECUTE             Execution Type      : TEST EXECUTE
Description         :                          Description         :
Scope               : COMPREHENSIVE            Scope               : COMPREHENSIVE
Status              : COMPLETED                Status              : COMPLETED
Started             : 05/21/2007 11:22:06      Started             : 05/21/2007 11:25:56
Last Updated        : 05/21/2007 11:24:01      Last Updated        : 05/21/2007 11:28:30
Global Time Limit   : 1800                     Global Time Limit   : 1800
Per-SQL Time Limit  : UNUSED                   Per-SQL Time Limit  : UNUSED
Number of Errors    : 0                        Number of Errors    : 0

---------------------------------------------------------------------------------------------

Result Summary

The Result Summary section summarizes the results of the SQL Performance Analyzer task. The Result Summary section is divided into the following subsections:

- Overall Performance Statistics

- Performance Statistics of SQL Statements

- Errors

Overall Performance Statistics

The Overall Performance Statistics subsection displays statistics about the overall performance of the entire SQL workload. This section is a very important part of the SQL Performance Analyzer analysis because it shows the impact of the system change on the overall performance of the SQL workload. Use the information in this section to understand the change of the workload performance, and determine whether the workload performance will improve or degrade after making the system change.

Example 6-2 shows the Overall Performance Statistics subsection of a sample report.

This example indicates that the overall performance of the SQL workload improved by 47.94%, even though regressions had a negative impact of -10.08%. This means that if all of the regressions are fixed in this example, the overall change impact will be 58.02%. After the system change, 2 of the 101 SQL statements ran faster, while 1 ran slower. Performance of 98 statements remained unchanged.

Example 6-2 Overall Performance Statistics

Report Summary
---------------------------------------------------------------------------------------------

Projected Workload Change Impact:
-------------------------------------------
Overall Impact      :   47.94%
Improvement Impact  :   58.02%
Regression Impact   :  -10.08%

SQL Statement Count
-------------------------------------------
SQL Category  SQL Count  Plan Change Count
Overall       101        6
Improved      2          2
Regressed     1          1
Unchanged     98         3
.
.
.
---------------------------------------------------------------------------------------------

Performance Statistics of SQL Statements

The Performance Statistics subsection highlights the SQL statements that are the most impacted by the system change. The pre-change and post-change performance data for each SQL statement in the workload are compared based on the following criteria:

- Execution frequency, or importance, of each SQL statement

- Impact of the system change on each SQL statement relative to the entire SQL workload

- Impact of the system change on each SQL statement

- Whether the structure of the execution plan for each SQL statement has changed

Example 6-3 shows the Performance Statistics of SQL Statements subsection of a sample report. The report has been altered slightly to fit on the page.

The SQL statements are sorted in descending order by the absolute value of the net impact on the SQL workload, that is, the sort order does not depend on whether the impact was positive or negative.

Example 6-3 Performance Statistics of SQL Statements

SQL Statements Sorted by their Absolute Value of Change Impact on the Workload
---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------
|           |               | Impact on | Execution |  Metric  |  Metric  | Impact | Plan   |
| object_id | sql_id        | Workload  | Frequency |  Before  |  After   | on SQL | Change |
---------------------------------------------------------------------------------------------
|    205    | 73s2sgy2svfrw |   29.01%  |   100000  |  1681683 |  220590  | 86.88% |   y    |
|    206    | gq2a407mv2hsy |   29.01%  |   949141  |  1681683 |  220590  | 86.88% |   y    |
|    204    | 2wtgxbjz6u2by |  -10.08%  |   478254  |  1653012 |  2160529 | -30.7% |   y    |
---------------------------------------------------------------------------------------------

Errors

The Errors subsection reports all errors that occurred during an execution. An error may be reported at the SQL tuning set level if it is common to all executions in the SQL tuning set, or at the execution level if it is specific to a SQL statement or execution plan.

Example 6-4 shows an example of the Errors subsection of a SQL Performance Analyzer report.

Example 6-4 Errors

----------------------------------------------------------------------------------
SQL STATEMENTS WITH ERRORS
----------------------------------------------------------------------------------
SQL ID        Error
------------- --------------------------------------------------------------------
47bjmcdtw6htn ORA-00942: table or view does not exist
br61bjp4tnf7y ORA-00920: invalid relational operator
----------------------------------------------------------------------------------

Result Details

The Result Details section represents a drill-down into the performance of SQL statements that appears in the Result Summary section of the report. Use the information in this section to investigate why the performance of a particular SQL statement regressed.

This section will contain an entry of every SQL statement processed in the SQL performance impact analysis. Each entry is organized into the following subsections:

- SQL Details

- Execution Statistics

- Execution Plans

SQL Details

This section of the report summarizes the SQL statement, listing its information and execution details.

Example 6-5 shows the SQL Details subsection of a sample report.

In Example 6-5, the report summarizes the regressed SQL statement whose ID is 2wtgxbjz6u2by and corresponding object ID is 204.

Example 6-5 SQL Details

SQL Details:
-----------------------------
Object ID            : 204
Schema Name          : APPS
SQL ID               : 2wtgxbjz6u2by
Execution Frequency  : 1
SQL Text             : SELECT /* my_query_14_scott */ /*+ ORDERED INDEX(t1)
USE_HASH(t1) */ 'B' || t2.pg_featurevalue_05_id
pg_featurevalue_05_id, 'r' || t4.elementrange_id
pg_featurevalue_15_id, 'G' || t5.elementgroup_id
pg_featurevalue_01_id, 'r' || t6.elementrange_id . . .
.
.
.
---------------------------------------------------------------------------------------------

Execution Statistics

The Execution Statistics subsection compares execution statistics of the SQL statement from the pre-change and post-change executions and then summarizes the findings.

Example 6-6 shows the Execution Statistics subsection of a sample report.

Example 6-6 Execution Statistics

Execution Statistics:
-----------------------------
---------------------------------------------------------------------------------------
|              | Impact on | Value   | Value   | Impact     | % Workload | % Workload |
| Stat Name    | Workload  | Before  | After   | on SQL     | Before     | After      |
---------------------------------------------------------------------------------------
| elapsed_time |    -95.54%|  36.484 | 143.161 |   -292.39% |     32.68% |     94.73% |
| parse_time   |    -12.37%|    .004 |    .062 |     -1450% |       .85% |     11.79% |
| exec_elapsed |    -95.89%|   36.48 | 143.099 |   -292.27% |     32.81% |     95.02% |
| exec_cpu     |    -19.73%|  36.467 |  58.345 |    -59.99% |     32.89% |     88.58% |
| buffer_gets  |    -10.08%| 1653012 | 2160529 |     -30.7% |     32.82% |     82.48% |
| cost         |     12.17%|   11224 |    2771 |     75.31% |     16.16% |      4.66% |
| reads        |  -1825.72%|    4091 |  455280 | -11028.82% |     16.55% |     96.66% |
| writes       |     -1500%|       0 |      15 |     -1500% |         0% |       100% |
| rows         |           |     135 |     135 |            |            |            |
---------------------------------------------------------------------------------------

Notes:
-----------------------------
Before Change:
1. The statement was first executed to warm the buffer cache.
2. Statistics shown were averaged over next 9 executions.

After Change:
1. The statement was first executed to warm the buffer cache.
2. Statistics shown were averaged over next 9 executions.

Findings (2):
-----------------------------
1. The performance of this SQL has regressed.
2. The structure of the SQL execution plan has changed.
---------------------------------------------------------------------------------------------

Execution Plans

The Execution Plans subsection displays the pre-change and post-change execution plans for the SQL statement. In cases when the performance regressed, this section also contains findings on root causes and symptoms.

Example 6-7 shows the Execution Plans subsection of a sample report.

Example 6-7 Execution Plans

Execution Plan Before Change:
-----------------------------
Plan Id          : 1
Plan Hash Value  : 3412943215

----------------------------------------------------------------------------------------------------------
| Id   | Operation                           | Name                | Rows   | Bytes   | Cost  | Time     |
----------------------------------------------------------------------------------------------------------
|    0 | SELECT STATEMENT                    |                     |      1 |     126 | 11224 | 00:02:15 |
|    1 |   HASH GROUP BY                     |                     |      1 |     126 | 11224 | 00:02:15 |
|    2 |    NESTED LOOPS                     |                     |      1 |     126 | 11223 | 00:02:15 |
|  * 3 |     HASH JOIN                       |                     |      1 |     111 | 11175 | 00:02:15 |
|  * 4 |      TABLE ACCESS FULL              | LU_ELEMENTGROUP_REL |      1 |      11 |   162 | 00:00:02 |
|  * 5 |      HASH JOIN                      |                     |    487 |   48700 | 11012 | 00:02:13 |
|    6 |       MERGE JOIN                    |                     |     14 |     924 |  1068 | 00:00:13 |
|    7 |        SORT JOIN                    |                     |   5391 |  274941 |  1033 | 00:00:13 |
|  * 8 |         HASH JOIN                   |                     |   5391 |  274941 |   904 | 00:00:11 |
|  * 9 |          TABLE ACCESS FULL          | LU_ELEMENTGROUP_REL |    123 |    1353 |   175 | 00:00:03 |
| * 10 |          HASH JOIN                  |                     |   5352 |  214080 |   729 | 00:00:09 |
| * 11 |           TABLE ACCESS FULL         | LU_ITEM_293         |   5355 |  128520 |    56 | 00:00:01 |
| * 12 |           TABLE ACCESS FULL         | ADM_PG_FEATUREVALUE |   1629 |   26064 |   649 | 00:00:08 |
| * 13 |        FILTER                       |                     |        |         |       |          |
| * 14 |         SORT JOIN                   |                     |      1 |      15 |    36 | 00:00:01 |
| * 15 |          TABLE ACCESS FULL          | LU_ELEMENTRANGE_REL |      1 |      15 |    35 | 00:00:01 |
|   16 |       INLIST ITERATOR               |                     |        |         |       |          |
| * 17 |        TABLE ACCESS BY INDEX ROWID  | FACT_PD_OUT_ITM_293 | 191837 | 6522458 |  9927 | 00:02:00 |
|   18 |         BITMAP CONVERSION TO ROWIDS |                     |        |         |       |          |
| * 19 |          BITMAP INDEX SINGLE VALUE  | FACT_274_PER_IDX    |        |         |       |          |
| * 20 |     TABLE ACCESS FULL               | LU_ELEMENTRANGE_REL |      1 |      15 |    49 | 00:00:01 |
----------------------------------------------------------------------------------------------------------
.
.
.

Execution Plan After Change:
-----------------------------
Plan Id          : 102
Plan Hash Value  : 1923145679

------------------------------------------------------------------------------------------------------
| Id   | Operation                           | Name                | Rows | Bytes  | Cost | Time     |
------------------------------------------------------------------------------------------------------
|    0 | SELECT STATEMENT                    |                     |    1 |    126 | 2771 | 00:00:34 |
|    1 |   HASH GROUP BY                     |                     |    1 |    126 | 2771 | 00:00:34 |
|    2 |    NESTED LOOPS                     |                     |    1 |    126 | 2770 | 00:00:34 |
|  * 3 |     HASH JOIN                       |                     |    1 |    111 | 2722 | 00:00:33 |
|  * 4 |      HASH JOIN                      |                     |    1 |    100 | 2547 | 00:00:31 |
|  * 5 |       TABLE ACCESS FULL             | LU_ELEMENTGROUP_REL |    1 |     11 |  162 | 00:00:02 |
|    6 |       NESTED LOOPS                  |                     |      |        |      |          |
|    7 |        NESTED LOOPS                 |                     |  484 |  43076 | 2384 | 00:00:29 |
|  * 8 |         HASH JOIN                   |                     |   14 |    770 |  741 | 00:00:09 |
|    9 |          NESTED LOOPS               |                     |    4 |    124 |  683 | 00:00:09 |
| * 10 |           TABLE ACCESS FULL         | LU_ELEMENTRANGE_REL |    1 |     15 |   35 | 00:00:01 |
| * 11 |           TABLE ACCESS FULL         | ADM_PG_FEATUREVALUE |    4 |     64 |  649 | 00:00:08 |
| * 12 |          TABLE ACCESS FULL          | LU_ITEM_293         | 5355 | 128520 |   56 | 00:00:01 |
|   13 |         BITMAP CONVERSION TO ROWIDS |                     |      |        |      |          |
| * 14 |          BITMAP INDEX SINGLE VALUE  | FACT_274_ITEM_IDX   |      |        |      |          |
| * 15 |        TABLE ACCESS BY INDEX ROWID  | FACT_PD_OUT_ITM_293 |   36 |   1224 | 2384 | 00:00:29 |
| * 16 |      TABLE ACCESS FULL              | LU_ELEMENTGROUP_REL |  123 |   1353 |  175 | 00:00:03 |
| * 17 |     TABLE ACCESS FULL               | LU_ELEMENTRANGE_REL |    1 |     15 |   49 | 00:00:01 |
------------------------------------------------------------------------------------------------------

Comparing SQL Tuning Sets Using APIs

You can compare two SQL tuning sets using the DBMS_SQLPA package. For example, while using Database Replay, you may have captured a SQL tuning set on the production system during workload capture, and another SQL tuning set on a test system during workload replay. You can then use SQL Performance Analyzer to compare these SQL tuning sets, without having to re-execute the SQL statements. This is useful in cases where you already have another utility to run your workload before and after making the system change, such as a custom script.

When comparing SQL tuning sets, SQL Performance Analyzer uses the runtime statistics captured in the SQL tuning sets to perform its comparison analysis, and reports on any new or missing SQL statements that are found in one SQL tuning set, but not in the other. Any changes in execution plans between the two SQL tuning sets are also reported. For each SQL statement in both SQL tuning sets, improvement and regression findings are reported for each SQL statement—calculated based on the average statistic value per execution—and for the entire workload—calculated based on the cumulative statistic value.

To compare SQL tuning sets using APIs:

1. Create a SQL Performance Analyzer task:

VAR aname varchar2(30);
EXEC :aname := 'compare_s2s';
EXEC :aname := DBMS_SQLPA.CREATE_ANALYSIS_TASK(task_name => :aname);

It is not necessary to associate a SQL tuning set to the task during creation.

2. Create the first SQL trial and convert the first SQL tuning set:

EXEC DBMS_SQLPA.EXECUTE_ANALYSIS_TASK(task_name => :aname, -
execution_type => 'convert sqlset', -
execution_name => 'first trial', -
execution_params => DBMS_ADVISOR.ARGLIST(
'sqlset_name', 'my_first_sts', -
'sqlset_owner', 'APPS'));

Specify the name and owner of the SQL tuning set using the SQLSET_NAME and SQLSET_OWNER task parameters. The content of the SQL tuning set will not be duplicated by the SQL Performance Analyzer task. Instead, a reference to the SQL tuning set is recorded in association to the new SQL trial, which in this example is "first trial".

3. Create a second SQL trial and associate it to the second SQL tuning second to which you want to compare:

EXEC DBMS_SQLPA.EXECUTE_ANALYSIS_TASK(task_name => :aname, -
execution_type => 'convert sqlset', -
execution_name => 'second trial', -
execution_params => DBMS_ADVISOR.ARGLIST(
'sqlset_name', 'my_second_sts', -
'sqlset_owner', 'APPS'));

4. Compare the performance data from the two SQL trials (or SQL tuning sets) by running a comparison analysis:

EXEC DBMS_SQLPA.EXECUTE_ANALYSIS_TASK(task_name => :aname, -
execution_type => 'compare', -
execution_name => 'comparison', -
execution_params => DBMS_ADVISOR.ARGLIST(
'workload_impact_threshold', 0, -
'sql_impact_threshold', 0));

In this example, the workload and per-SQL impact threshold are set to 0% for comparison (the default value is 1%).

5. After the comparison analysis is complete, generate a SQL Performance Analyzer report using the DBMS_SQLPA.REPORT_ANALYSIS_TASK function.
For information about generating a SQL Performance Analyzer report using APIs, see "Analyzing SQL Performance Using APIs".

Once the report is generated, review it to identify any differences between the contents of the two SQL tuning sets. Example 6-8 shows the Analysis Information and Report Summary sections of a sample report generated by comparing two SQL tuning sets:

Example 6-8 Analysis Information and Report Summary

Analysis Information:
------------------------------------------------------------------------------------------------
Before Change Execution:                          After Change Execution:
---------------------------------------------     ---------------------------------------------
Execution Name      : first trial                 Execution Name      : second trial
Execution Type      : CONVERT SQLSET              Execution Type      : CONVERT SQLSET
Status              : COMPLETED                   Status              : COMPLETED
Started             : …
Last Updated        : …

Before Change Workload:                           After Change Workload:
---------------------------------------------     ---------------------------------------------
SQL Tuning Set Name        : my_first_sts         SQL Tuning Set Name        : my_second_sts
SQL Tuning Set Owner       : APPS                 SQL Tuning Set Owner       : APPS
Total SQL Statement Count  : 5                    Total SQL Statement Count  : 6

------------------------------------------------------------------------------------------------
Report Summary
------------------------------------------------------------------------------------------------

Projected Workload Change Impact:
-------------------------------------------
Overall Impact      :  72.32%
Improvement Impact  :  47.72%
Regression Impact   :   -.02%
Missing-SQL Impact  :   33.1%
New-SQL Impact      :  -8.48%

SQL Statement Count
-------------------------------------------
SQL Category   SQL Count  Plan Change Count
Overall                7                  1
Common                 4                  1
Improved              3                  1
Regressed             1                  0
Different              3                  0
Missing SQL           1                  0
New SQL               2                  0

As shown in Example 6-8, this report contains two additional categories that are not found in standard SQL Performance Analyzer reports; both categories are grouped under the heading Different:

- Missing SQL
This category represents all SQL statements that are present in the first SQL tuning set, but are not found in the second SQL tuning set. In this example, only one SQL statement is missing. As shown in Example 6-9, this SQL statement has:

- A sql_id value of gv7xb8tyd1v91

- A performance impact on the workload of 33.1% based on the change

- No performance impact on the SQL statement based on the change because its "Total Metric After" change value is missing

- New SQL
This category represents all SQL statements that are present in the second SQL tuning set, but are not found in the first SQL tuning set. In this example, only two SQL statements are new in the second SQL tuning set. As shown in Example 6-9, these SQL statements have:

- sql_id values of 4c8nrqxhtb2sf and 9utadgu5udmh4

- A total performance impact on the workload of -8.48%

- Missing "Total Metric Before" change values

Example 6-9 shows a table in the sample report that lists the missing and new SQL statements, as well as other top SQL statements as determined by their impact on the workload:

Example 6-9 Top 7 SQL Sorted by Absolute Value of Change Impact on the Workload

Top 7 SQL Sorted by Absolute Value of Change Impact on the Workload
------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------
|           |               | Impact on | Total Metric | Total Metric | Impact  | Plan   |
| object_id | sql_id        | Workload  |    Before    |    After     | on SQL  | Change |
------------------------------------------------------------------------------------------
|         4 | 7gj3w9ya4d9sj |    41.04% |       812791 |        36974 |     95% | y      |
|         7 | gv7xb8tyd1v91 |     33.1% |       625582 |              |         | n      |
|         2 | 4c8nrqxhtb2sf |    -8.35% |              |       157782 |         | n      |
|         1 | 22u3tvrt0yr6g |     4.58% |       302190 |       215681 |  28.63% | n      |
|         6 | fgdd0fd56qmt0 |      2.1% |       146128 |       106369 |  27.21% | n      |
|         5 | 9utadgu5udmh4 |     -.13% |              |         2452 |         | n      |
|         3 | 4dtv43awxnmv3 |     -.02% |         3520 |         3890 | -47.35% | n      |
------------------------------------------------------------------------------------------

Once you have identified a SQL statement of interest, you can generate a report for the SQL statement to perform more detailed investigation. For example, you may want to investigate the SQL statement with the sql_id value of 7gj3w9ya4d9sj and object_id value of 4 because it has the highest impact on the workload:

SELECT DBMS_SQLPA.REPORT_ANALYSIS_TASK(task_name => :aname, object_id => 4) rep
FROM dual;

Example 6-10 shows a sample report generated for this SQL statement:

Example 6-10 Sample Report for SQL Statement

SQL Details:
-----------------------------
Object ID  : 4
SQL ID     : 7gj3w9ya4d9sj
SQL Text   : /* my_csts_query1 */ select * FROM emp where empno=2

SQL Execution Statistics (average):
---------------------------------------
---------------------------------------------------------
|              | Impact on | Value   | Value   | Impact |
| Stat Name    | Workload  | Before  | After   | on SQL |
---------------------------------------------------------
| elapsed_time |    41.04% | .036945 | .001849 |    95% |
| cpu_time     |    13.74% | .004772 |  .00185 | 61.24% |
| buffer_gets  |     9.59% |       8 |       2 | 69.01% |
| cost         |    11.76% |       1 |       1 |    10% |
| reads        |     4.08% |       0 |       0 | 63.33% |
| writes       |        0% |       0 |       0 |     0% |
| rows         |           |       0 |       0 |        |
| executions   |           |      22 |      20 |        |
| plan_count   |           |       3 |       2 |        |
---------------------------------------------------------
Findings (2):
-----------------------------
1. The performance of this SQL has improved.
2. The structure of the SQL execution plan has changed.

Plan Execution Statistics (average):
---------------------------------------
----------------------------------------------------------------------------------
| Statistic Name  | Plans Before Change              | Plans After Change        |
----------------------------------------------------------------------------------
| plan hash value | 440231712  571903972  3634526668 | 571903972  3634526668     |
| --------------- | ---------  ---------  ---------- | ---------  ----------     |
|  schema name    | APPS1      APPS2      APPS2      | APPS2      APPS2          |
|  executions     | 7          5          10         | 10         10             |
|  cost           | 2          1          2          | 1          2              |
|  elapsed_time   | .108429    .000937    .00491     | .000503    .003195        |
|  cpu_time       | .00957     .0012      .0032      | .0005      .0032          |
|  buffer_gets    | 18         0          5          | 0          5              |
|  reads          | 0          0          0          | 0          0              |
|  writes         | 0          0          0          | 0          0              |
|  rows           | 0          0          0          | 0          0              |
----------------------------------------------------------------------------------
Execution Plans Before Change:
-----------------------------
Plan Hash Value  : 440231712
---------------------------------------------------------------------------
| Id | Operation              | Name     | Rows | Bytes | Cost | Time     |
---------------------------------------------------------------------------
|  0 | SELECT STATEMENT       |          |      |       |    2 |          |
|  1 |   PX COORDINATOR       |          |      |       |      |          |
|  2 |    PX SEND QC (RANDOM) | :TQ10000 |    1 |    87 |    2 | 00:00:01 |
|  3 |     PX BLOCK ITERATOR  |          |    1 |    87 |    2 | 00:00:01 |
|  4 |      TABLE ACCESS FULL | EMP      |    1 |    87 |    2 | 00:00:01 |
---------------------------------------------------------------------------
Note
-----
- dynamic sampling used for this statement
Plan Hash Value  : 571903972
----------------------------------------------------------------------------------
| Id | Operation                     | Name       | Rows | Bytes | Cost | Time   |
----------------------------------------------------------------------------------
|  0 | SELECT STATEMENT              |            |      |       |    1 |        |
|  1 |   TABLE ACCESS BY INDEX ROWID | EMP        |    1 |    87 |    1 |00:00:01|
|  2 |    INDEX UNIQUE SCAN          | MY_EMP_IDX |    1 |       |    0 |        |
----------------------------------------------------------------------------------
Plan Hash Value  : 3634526668
--------------------------------------------------------------------
| Id | Operation           | Name | Rows | Bytes | Cost | Time     |
--------------------------------------------------------------------
|  0 | SELECT STATEMENT    |      |      |       |    2 |          |
|  1 |   TABLE ACCESS FULL | EMP  |    1 |    87 |    2 | 00:00:01 |
--------------------------------------------------------------------
Note
-----
- dynamic sampling used for this statement

Executions Plan After Change:
-----------------------------
Plan Hash Value  : 571903972
----------------------------------------------------------------------------------
| Id | Operation                     | Name       | Rows | Bytes | Cost | Time   |
----------------------------------------------------------------------------------
|  0 | SELECT STATEMENT              |            |      |       |    1 |        |
|  1 |   TABLE ACCESS BY INDEX ROWID | EMP        |    1 |    87 |    1 |00:00:01|
|  2 |    INDEX UNIQUE SCAN          | MY_EMP_IDX |    1 |       |    0 |        |
----------------------------------------------------------------------------------
Plan Hash Value  : 3634526668
--------------------------------------------------------------------
| Id | Operation           | Name | Rows | Bytes | Cost | Time     |
--------------------------------------------------------------------
|  0 | SELECT STATEMENT    |      |      |       |    2 |          |
|  1 |   TABLE ACCESS FULL | EMP  |    1 |    87 |    2 | 00:00:01 |
--------------------------------------------------------------------
Note
-----
- dynamic sampling used for this statement
----------------------------------------------------------------------------------

The SQL Execution Statistics section shows the average runtime statistics (per execution) of the SQL statement. The data in this table reveals that this SQL statement is present in both SQL tuning sets, but that it has only three execution plans in the first SQL tuning set and two execution plans in the second SQL tuning set. Furthermore, the SQL statement was executed 22 times in the first SQL tuning set, but only 20 times in the second SQL tuning set.

The Plan Execution Statistics section shows runtime statistics per execution plan (or plan hash value). The Plans Before Change column lists plans and their associated execution statistics for the first SQL tuning set; the Plans After Change columns lists these values for the second SQL tuning set. Execution plans structures for both SQL tuning sets are shown at the end of the report.

You can use these sections in the report to identify changes in execution plans between two SQL tuning sets. This is important because changes in execution plans may be a result of test changes that can have a direct impact to performance. When comparing two SQL tuning sets, SQL Performance Analyzer reports execution plan changes when a SQL statement has:

- One plan in both SQL tuning sets, but the plan structure is different

- More than one plan, and the number of plans in both SQL tuning sets are:

- The same, but at least one plan in the second SQL tuning set is different from all plans in the first SQL tuning set

- Different

After evaluating the SQL statement and plan changes, determine if further action is required. If the SQL statement has regressed, perform one of the following actions:

- Tune the regressed SQL statement, as described in "Tuning Regressed SQL Statements Using APIs"

- Create SQL plan baselines, as described in "Creating SQL Plan Baselines Using APIs"

Tuning Regressed SQL Statements Using APIs

After reviewing the SQL Performance Analyzer report, you should tune any regressed SQL statements that are identified after comparing the SQL performance. If there are large numbers of SQL statements that appear to have regressed, you should try to identify the root cause and make system-level changes to rectify the problem. In cases when only a few SQL statements have regressed, consider using the SQL Tuning Advisor to implement a point solution for them, or creating SQL plan baselines to instruct the optimizer to select the original execution plan in the future.

To tune regressed SQL statements using APIs:

- Create a SQL tuning task for the SQL Performance Analyzer execution by using the CREATE_TUNING_TASK function in the DBMS_SQLTUNE package:

BEGIN
DBMS_SQLTUNE.CREATE_TUNING_TASK(
spa_task_name => 'my_spa_task',
spa_task_owner => 'immchan',
spa_compare_exec => 'my_exec_compare');
DBMS_SQLTUNE.EXECUTE_TUNING_TASK(spa_task_name => 'my_spa_task');
END;
/

This example creates and executes a SQL tuning task to tune the SQL statements that regressed in the compare performance execution named my_exec_compare of the SQL Performance Analyzer task named my_spa_task. In this case, it is important to use this version of the CREATE_TUNING_TASK function call. Otherwise, SQL statements may be tuned in the environment from the production system where they were captured, which will not reflect the system change.

Note:

If you chose to execute the SQL workload remotely on a separate database, you should not use this version of the CREATE_TUNING_TASK function call to tune regressed SQL statements. Instead, you should tune any regressions identified by the SQL trials on the remote database, because the application schema is not on the database running SQL Performance Analyzer. Therefore, you need to run SQL Tuning Advisor on the database where the schema resides and where the change was made. For more information, see "Tuning Regressed SQL Statements From a Remote SQL Trial Using APIs".

Table 6-1 lists the SQL Performance Analyzer parameters that can be used with the DBMS_SQLTUNE.CREATE_TUNING_TASK function.

Table 6-1 CREATE_TUNING_TASK Function SQL Performance Analyzer Parameters

Parameter

Description

SPA_TASK_NAME

Name of the SQL Performance Analyzer task.

SPA_TASK_OWNER

Owner of the specified SQL Performance Analyzer task. If unspecified, this parameter will default to the current user.

SPA_COMPARE_EXEC

Execution name of the compare performance trial for the specified SQL Performance Analyzer task. If unspecified, this parameter defaults to the most recent execution of the COMPARE PERFORMANCE type for the given SQL Performance Analyzer task.

After tuning the regressed SQL statements, you should test these changes using SQL Performance Analyzer. Run a new SQL trial on the test system, followed by a second comparison (between this new SQL trial and the first SQL trial) to validate your results. Once SQL Performance Analyzer shows that performance has stabilized, implement the fixes from this step to your production system.

Starting with Oracle Database 11g Release 2, SQL Tuning Advisor performs an alternative plan analysis when tuning a SQL statement. SQL Tuning Advisor reviews the execution history of the SQL statement, including any historical plans stored in the Automatic Workload Repository. If SQL Tuning Advisor finds alternate plans, it allows you to choose a specific plan and create a plan baseline to ensure that the desired execution plan is used for that SQL statement.

See Also:

- Oracle Database SQL Tuning Guide for information about using the SQL Tuning Advisor

- Oracle Database SQL Tuning Guide for information about alternative plan analysis

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_SQLTUNE package

Tuning Regressed SQL Statements From a Remote SQL Trial Using APIs

If you chose to execute the SQL workload remotely on a separate database, then you should tune any regressions identified by the SQL trials on the remote database, instead of the system where the SQL Performance Analyzer task resides.

To tune regressed SQL statements from a remote SQL trial using APIs:

1. On the system running SQL Performance Analyzer, create a subset of the regressed SQL statements as a SQL tuning set:

DECLARE
sqlset_cur  DBMS_SQLTUNE.SQLSET_CURSOR;
BEGIN
DBMS_SQLTUNE.CREATE_SQLSET('SUB_STS1', 'test purpose');

OPEN sqlset_cur FOR
SELECT value(p)
FROM table(
DBMS_SQLTUNE.SELECT_SQLPA_TASK(
task_name  => 'SPA_TASK1',
execution_name => 'COMP',
level_filter => 'REGRESSED')) p;

DBMS_SQLTUNE.LOAD_SQLSET('SUB_STS1', sqlset_cur);

CLOSE sqlset_cur;
END;
/

Other than 'REGRESSED', you can use other filters to select SQL statements for the SQL tuning set, such as 'CHANGED', 'ERRORS', or 'CHANGED_PLANS'. For more information, see Oracle Database PL/SQL Packages and Types Reference.

2. Create a staging table to where the SQL tuning set will be exported:

BEGIN
DBMS_SQLTUNE.CREATE_STGTAB_SQLSET(
table_name  => 'STG_TAB1',
schema_name => 'JOHNDOE',
tablespace_name => 'TBS_1',
db_version => DBMS_SQLTUNE.STS_STGTAB_11_1_VERSION);
END;
/

Use the db_version parameter to specify the appropriate database version to where the SQL tuning set will be exported and tuned. In this example, the staging table will be created with a format so that it can be exported to a system running Oracle Database 11g Release 1, where it will later be tuned using SQL Tuning Advisor. For other database versions, see Oracle Database PL/SQL Packages and Types Reference for that release.

3. Export the SQL tuning set into the staging table:

BEGIN
DBMS_SQLTUNE.PACK_STGTAB_SQLSET(
sqlset_name => 'SUB_STS1',
sqlset_owner => 'JOHNDOE',
staging_table_name => 'STG_TAB1',
staging_schema_owner => 'JOHNDOE',
db_version => DBMS_SQLTUNE.STS_STGTAB_11_1_VERSION);
END;
/

4. Move the staging table to the remote database (where the SQL workload was executed) using the mechanism of choice (such as Oracle Data Pump or database link).

5. On the remote database, import the SQL tuning set from the staging table:

BEGIN
DBMS_SQLTUNE.UNPACK_STGTAB_SQLSET(
sqlset_name => 'SUB_STS1',
staging_table_name => 'STG_TAB1',
replace => TRUE);
END;
/

6. Tune the regressed SQL statements in the SQL tuning set by running SQL Tuning Advisor:

BEGIN
sts_name  := 'SUB_STS1';
sts_owner := 'JOHNDOE';
tune_task_name := 'TUNE_TASK1';
tname := DBMS_SQLTUNE.CREATE_TUNING_TASK(sqlset_name  => sts_name,
sqlset_owner => sts_owner,
task_name    => tune_task_name);
EXEC DBMS_SQLTUNE.SET_TUNING_TASK_PARAMETER(:tname,
'APPLY_CAPTURED_COMPILENV',
'FALSE');
exec_name := DBMS_SQLTUNE.EXECUTE_TUNING_TASK(tname);
END;
/

Note:

The APPLY_CAPTURED_COMPILENV parameter used in this example is only supported by Oracle Database 11g Release 1 and newer releases. If you are testing a database upgrade from an earlier version of Oracle Database, SQL Tuning Advisor will use the environment variables stored in the SQL tuning set instead.

After tuning the regressed SQL statements, you should test these changes using SQL Performance Analyzer. Run a new SQL trial on the test system, followed by a second comparison (between this new SQL trial and the first SQL trial) to validate your results. Once SQL Performance Analyzer shows that performance has stabilized, implement the fixes from this step to your production system.

See Also:

- Oracle Database SQL Tuning Guide for information about using the SQL Tuning Advisor and transporting SQL tuning sets

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_SQLTUNE package

Creating SQL Plan Baselines Using APIs

Creating SQL plan baselines for regressed SQL statements with plan changes is another option to running the SQL Tuning Advisor. Doing so instructs the optimizer to use the original execution plans for these SQL statements in the future.

To create SQL plan baselines for the original plans:

1. Create a subset of a SQL tuning set of only the regressed SQL statements.

2. Create SQL plan baselines for this subset of SQL statements by loading their plans using the LOAD_PLANS_FROM_SQLSET function of the DBMS_SPM package, as shown in the following example:

DECLARE
my_plans PLS_INTEGER;
BEGIN
my_plans := DBMS_SPM.LOAD_PLANS_FROM_SQLSET(
sqlset_name => 'regressed_sql');
END;
/

See Also:

- Oracle Database SQL Tuning Guide for information about using SQL plan baselines

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_SPM package

Using SQL Performance Analyzer Views

You can query the following views to monitor SQL Performance Analyzer and view its analysis results:

Note:

The information available in these views are also contained in the SQL Performance Analyzer report. It is recommended that you use the SQL Performance Analyzer report to view analysis results instead. Consider using these views only for performing more advanced analysis of the results.

- The DBA_ADVISOR_TASKS and USER_ADVISOR_TASKS views display descriptive information about the SQL Performance Analyzer task that was created.

- The DBA_ADVISOR_EXECUTIONS and USER_ADVISOR_EXECUTIONS views display information about task executions. SQL Performance Analyzer creates at least three executions to analyze the SQL performance impact caused by a database change on a SQL workload. The first execution collects a pre-change version of the performance data. The second execution collects a post-change version of the performance data. The third execution performs the comparison analysis.

- The DBA_ADVISOR_FINDINGS and USER_ADVISOR_FINDINGS views display the SQL Performance Analyzer findings. SQL Performance Analyzer generates the following types of findings:

- Problems, such as performance regression

- Symptoms, such as when the structure of an execution plan has changed

- Errors, such as nonexistence of an object or view

- Informative messages, such as when the structure of an execution plan in the pre-change version is different than the one stored in the SQL tuning set

- The DBA_ADVISOR_SQLPLANS and USER_ADVISOR_SQLPLANS views display a list of all execution plans.

- The DBA_ADVISOR_SQLSTATS and USER_ADVISOR_SQLSTATS views display a list of all SQL compilations and execution statistics.

- The V$ADVISOR_PROGRESS view displays the operation progress of SQL Performance Analyzer. Use this view to monitor how many SQL statements have completed or are awaiting execution in a SQL trial. The SOFAR column indicates the number of SQL statements processed so far, and the TOTAL WORK column shows the total number of SQL statements to be processed by the task execution.

You must have the SELECT_CATALOG_ROLE role to access the DBA views.

See Also:

- Oracle Database Reference for information about the DBA_ADVISOR_TASKS, DBA_ADVISOR_EXECUTIONS, and DBA_ADVISOR_SQLPLANS views

7 Using SPA Quick Check

Oracle Enterprise Manager Cloud Control (Cloud Control) includes the SQL Performance Analyzer Quick Check (SPA Quick Check) feature. On some Cloud Control database management pages, SPA Quick Check can validate the impact of a system change to the database workload before you make the change.

You can use SPA Quick Check to validate what the impact to your database workload will be for the following changes:

- Changing the value of an initialization parameter

- Gathering pending optimizer statistics

- Implementing key SQL profiles

Note:

SPA Quick Check is available starting with Cloud Control Release 12.1.0.4 Bundle Patch 8 and later.

SPA Quick Check is supported for any database running Oracle Database 10g Release 2 (10.2) and later. However, not all the SPA Quick Check features are supported in Oracle Database 10g Release 2 (10.2).

For example, optimizer pending statistics and Automatic SQL Tuning Advisor features are available starting with Oracle Database 11g Release 1 (11.1), so SPA Quick Check workflows for these features are only supported for databases running Oracle Database 11g Release 1 (11.1) and later.

See Also:

- "About Configuring SPA Quick Check"

- "Specifying Default Values for SPA Quick Check"

- "Validating the Impact of an Initialization Parameter Change"

- "Validating the Impact of Pending Optimizer Statistics"

- "Validating the Impact of Implementing Key SQL Profiles"

- "Validating Statistics Findings from Automatic SQL Tuning Advisor"

About Configuring SPA Quick Check

Before you can use SPA Quick Check to validate the impact of an initialization parameter change or of gathering pending optimizer statistics, you must specify default settings for SPA Quick Check.

You will specify a default SQL tuning set for SPA Quick Check to use as one of the settings, and this SQL tuning set should include SQL statements used in the database application you are trying to tune.

Note:

It is not necessary to set default values for SPA Quick Check before using SPA Quick Check to validate the impact of implementing one or more key SQL profiles.

See Also:

- "Using SPA Quick Check"

- "Specifying Default Values for SPA Quick Check"

- "Validating the Impact of an Initialization Parameter Change"

- "Validating the Impact of Pending Optimizer Statistics"

- "Validating the Impact of Implementing Key SQL Profiles"

- "Validating Statistics Findings from Automatic SQL Tuning Advisor"

Specifying Default Values for SPA Quick Check

You specify default settings for SPA Quick Check on the SQL Performance Analyzer Setup page in Cloud Control.

To specify default settings for SPA Quick Check:

1. On the Database Home page in Cloud Control, from the Performance menu, select SQL, then SQL Performance Analyzer Setup. If the Database Login page appears, enter administrator privileges for the database, then click Login.The SQL Performance Analyzer Setup page appears.

2. Configure the settings for the SPA Quick Check feature, which is available on some Cloud Control database management pages. The SQL tuning set that you specify should be representative of the workload for the application that you want to tune.

3. Click Save to save the default SPA Quick Check settings you specified.

Validating the Impact of an Initialization Parameter Change

Before you change the value of a session-modifiable initialization parameter, you can validate the impact of that change on your database workload by using SPA Quick Check. Session-modifiable parameters are initialization parameters whose values can be changed using the ALTER SESSION statement.

Note:

You can use SPA Quick Check to validate the impact of an initialization parameter change in databases running Oracle Database 10g Release 2 (10.2) and later.

To validate the impact of an initialization parameter change:

1. On the Database Home page in Cloud Control, from the Administration menu, select Initialization Parameters.The Initialization Parameters page appears.

2. Use the filter on the Initialization Parameters page to identify the session-modifiable initialization parameter whose value you want to change, and click Go to display that parameter in the table at the bottom of the page. Most of the parameters in the Optimizer category are session-modifiable.

3. In the table, change the current value of the parameter to the new value whose impact you would like to validate using SPA Quick Check.

4. Click Validate with SPA.

An Information message appears at the top of the page, and says that a SPA task for validating the impact of the initialization parameter change has been submitted.

5. Click the link for the SPA task in the Information message.The SQL Performance Analyzer Home page appears.

6. In the SQL Performance Analyzer Tasks section at the bottom of the page, select the task for the initialization parameter job, and click View Latest Report.The SQL Performance Analyzer Task Report page appears.

7. View the table at the bottom of the page to see what the result of changing the initialization parameter's value would be on the most impactful SQL statements in the workload.

Validating the Impact of Pending Optimizer Statistics

Before you gather pending optimizer statistics, you can validate the impact of gathering those statistics on your database workload by using SPA Quick Check.

Note:

You can use SPA Quick Check to validate the impact of gathering pending optimizer statistics in databases running Oracle Database 11g Release 1 (11.1) and later.

To validate the impact of gathering pending optimizer statistics:

1. On the Database Home page in Cloud Control, from the Performance menu, select SQL, and then Optimizer Statistics.The Optimizer Statistics Console page appears.

2. In the Operations section, click Gather.The Gather Optimize Statistics wizard appears.

3. In the Validate with SQL Performance Analyzer section at the bottom of the Gather Optimizer Statistics: Scope page, enable the Validate impact of stats on SQL performance prior to publishing (recommended) option. The database global statistics gathering option PUBLISH will be set to FALSE temporarily during the process. Then click Next.

4. Continue through the wizard, and on the Gather Optimizer Statistics: Scope page, click Submit.Along with gathering pending statistics, this starts a job that creates a SQL Performance Analyzer task that validates the impact of gathering optimizer statistics for the database.

5. When the job starts, a Confirmation message appears on the Manage Optimizer Statistics page that says that the Gather Optimizer Statistics job has been successfully submitted. Click the link in that message.The SQL Performance Analyzer Home page appears.

6. In the SQL Performance Analyzer Tasks table at the bottom of the page, make sure that the statistics gathering job has completed. It may take several minutes for the job to complete. Then select the row for the Gather Optimizer Statistics job and click View Latest Report.The SQL Performance Analyzer Task Report page appears.

7. View the table at the bottom of the page to see what the result of publishing the pending optimizer statistics would be on the most impactful SQL statements in the workload.

Validating the Impact of Implementing Key SQL Profiles

Before you implement key SQL profiles for SQL statements, you can validate the impact of using those profiles by using SPA Quick Check. You can validate the impact of key SQL profiles on the Automatic SQL Tuning Result Summary page. Key SQL profiles are profiles verified to yield at least a 3 times performance improvement, and which would have been implemented automatically if auto-implementation had been enabled for Automatic SQL Tuning Advisor.

Note:

You can use SPA Quick Check to validate the impact of implementing key SQL profiles in databases running Oracle Database 11g Release 1 (11.1) and later.

To validate the impact of key SQL profiles:

1. On the Database Home page in Cloud Control, from the Performance menu, select Advisors Home.The Advisor Central page appears.

2. In the Advisors section, click SQL Advisors.The SQL Advisors page appears.

3. In the SQL Tuning Advisor section, click Automatic SQL Tuning Results.The Automatic SQL Tuning Result Summary page appears.

4. The Key SQL Profiles field in the Task Status section lists the number of key SQL profiles for the current automatic SQL tuning task. If a value of 0 appears in the field, there are no key SQL profiles to use (or validate). If a value greater than 0 appears in the Key SQL Profiles field, click the value to validate the impact of using the key SQL profile or profiles.The Automatic SQL Tuning Result Details: SQLs with Key SQL Profile page appears.

5. The key SQL profiles appear in the Recommendations section. Click Validate All Profiles with SPA.

A Confirmation statement appears at the top of the page that indicates that a SPA task for validating the SQL profiles has been submitted.

6. Click the link for the SPA task in the Confirmation statement.The SQL Performance Analyzer Home page appears, and the SPA task for validating the key SQL profiles appears in the SQL Performance Analyzer Tasks table at the bottom of the page.

7. Select the task and click View Latest Report.The SQL Performance Analyzer Task Report page appears.

8. View the table at the bottom of the page to see what the result would be of implementing the key SQL profiles recommended on the Automatic SQL Tuning Result Summary page on the most impactful SQL statements in the workload.

Validating Statistics Findings from Automatic SQL Tuning Advisor

You can validate the impact of statistics findings from Automatic SQL Tuning Advisor using SPA Quick Check.

Note:

You can use SPA Quick Check to validate the impact of validating statistics findings from Automatic SQL Tuning Advisor in databases running Oracle Database 11g Release 1 (11.1) and later.

To validate the impact of statistics findings from Automatic SQL Tuning Advisor:

1. On the Database Home page in Cloud Control, from the Performance menu, select Advisors Home.The Advisor Central page appears.

2. In the Advisors section, click SQL Advisors.The SQL Advisors page appears.

3. In the SQL Tuning Advisor section, click Automatic SQL Tuning Results.The Automatic SQL Tuning Result Summary page appears.

4. If any statistics findings are available, they appear in the Statistics Finding Summary section near the bottom of the page. To validate the impact of statistics findings in user schemas, click Validate with SPA.A Confirmation statement appears at the top of the page that indicates a SPA task for validating the statistics findings has been submitted.

5. Click the link for the SPA task in the Confirmation statement.The SQL Performance Analyzer Home page appears, and the SPA task for validating the statistics findings appears in the SQL Performance Analyzer Tasks table at the bottom of the page.

6. After all the steps in the task have completed successfully, and Completed appears in the Last Run Status column of the table, select the task and click View Latest Report. It may take several minutes for all of the steps in the task to complete.The SQL Performance Analyzer Task Report page appears.

7. View the table at the bottom of the page to see what the result would be of implementing the statistics on the Automatic SQL Tuning Result Summary page on the most impactful SQL statements in the workload.

8 Testing a Database Upgrade

SQL Performance Analyzer supports testing database upgrades from Oracle9i and later releases to Oracle Database 10g Release 2 or newer releases. The methodology used to test a database upgrade from Oracle9i Database and Oracle Database 10g Release 1 is slightly different from the one used to test a database upgrade from Oracle Database 10g Release 2 and later releases, so both methodologies are described here.

This chapter describes how to use SQL Performance Analyzer in a database upgrade and contains the following sections:

- Upgrading from Oracle9i Database and Oracle Database 10g Release 1

- Upgrading from Oracle Database 10g Release 2 and Newer Releases

- Tuning Regressed SQL Statements After Testing a Database Upgrade

See Also:

- "SQL Performance Analyzer" for information about using SQL Performance Analyzer in other cases

Upgrading from Oracle9i Database and Oracle Database 10g Release 1

As illustrated in Figure 8-1, SQL Performance Analyzer supports testing database upgrades of Oracle9i Database and Oracle Database 10g Release 1 to Oracle Database 10g Release 2 and newer releases by:

- Building a SQL tuning set from SQL trace files captured on the production system

- Executing the SQL tuning set on the upgraded database remotely over a database link

- Comparing the results to those captured on the production system

Because SQL Performance Analyzer only accepts a set of SQL statements stored in a SQL tuning set as its input source, and SQL tuning sets are not supported for Oracle9i Database, a SQL tuning set must be constructed so that it can be used as an input source for SQL Performance Analyzer if you are upgrading from Oracle9i Database.

Figure 8-1 SQL Performance Analyzer Workflow for Database Upgrade from Oracle9i to Oracle Database 10g Release 2

Before the database upgrade can be tested, ensure that the following conditions are met:

- The production system which you are upgrading from is running Oracle9i or Oracle Database 10g Release 1.

- The test system which you are upgrading to is running Oracle Database 10g Release 2 or a newer release.
The database version can be release 10.2.0.2 or higher. If you are upgrading to Oracle Database 10g release 10.2.0.2, 10.2.0.3, or 10.2.0.4, you will also need to install a one-off patch before proceeding.

- The test system must resemble the production system as closely as possible because the performance on both systems will be compared to each other.

- The hardware configurations on both systems must also be as similar as possible.

You will also need to set up a separate SQL Performance Analyzer system running Oracle Database 11g Release 2. You will be using this system to build a SQL tuning set and to run SQL Performance Analyzer. Neither your production data or schema need to be available on this system, since the SQL tuning set will be built using statistics stored in the SQL trace files from the production system. SQL Performance Analyzer tasks will be executed remotely on the test system to generate the execution plan and statistics for the SQL trial over a database link that you specify. The database link must be a public database link that connects to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the test system. You should also drop any existing PLAN_TABLE from the user's schema on the test system.

Once the upgrade environment is configured as described, perform the steps as described in the following procedure to use SQL Performance Analyzer in a database upgrade from Oracle9i or Oracle Database 10g Release 1 to a newer release.

1. Enable the SQL Trace facility on the production system, as described in "Enabling SQL Trace on the Production System".
To minimize the performance impact on the production system and still be able to fully capture a representative set of SQL statements, consider enabling SQL Trace for only a subset of the sessions, for as long as required, to capture all important SQL statements at least once.

2. On the production system, create a mapping table, as described in "Creating a Mapping Table".
This mapping table will be used to convert the user and object identifier numbers in the SQL trace files to their string equivalents.

3. Move the SQL trace files and the mapping table from the production system to the SQL Performance Analyzer system, as described in "Creating a Mapping Table".

4. On the SQL Performance Analyzer system, construct a SQL tuning set using the SQL trace files, as described in "Building a SQL Tuning Set".
The SQL tuning set will contain the SQL statements captured in the SQL trace files, along with their relevant execution context and statistics.

5. On the SQL Performance Analyzer system, use SQL Performance Analyzer to create a SQL Performance Analyzer task and convert the contents in the SQL tuning set into a pre-upgrade SQL trial that will be used as a baseline for comparison, then remotely test execute the SQL statements on the test system over a database link to build a post-upgrade SQL trial, as described in "Testing Database Upgrades from Oracle9i Database and Oracle Database 10g Release 1".

6. Compare SQL performance and fix regressed SQL.
SQL Performance Analyzer compares the performance of SQL statements read from the SQL tuning set during the pre-upgrade SQL trial to those captured from the remote test execution during the post-upgrade SQL trial. A report is produced to identify any changes in execution plans or performance of the SQL statements.

If the report reveals any regressed SQL statements, you can make further changes to fix the regressed SQL, as described in "Tuning Regressed SQL Statements After Testing a Database Upgrade".

Repeat the process of executing the SQL tuning set and comparing its performance to a previous execution to test any changes made until you are satisfied with the outcome of the analysis.

Enabling SQL Trace on the Production System

Oracle9i uses the SQL Trace facility to collect performance data on individual SQL statements. The information generated by SQL Trace is stored in SQL trace files. SQL Performance Analyzer consumes the following information from these files:

- SQL text and username under which parse occurred

- Bind values for each execution

- CPU and elapsed times

- Physical reads and logical reads

- Number of rows processed

- Execution plan for each SQL statement (only captured if the cursor for the SQL statement is closed)

Although it is possible to enable SQL Trace for an instance, it is recommended that you enable SQL Trace for a subset of sessions instead. When the SQL Trace facility is enabled for an instance, performance statistics for all SQL statements executed in the instance are stored into SQL trace files. Using SQL Trace in this way can have a severe performance impact and may result in increased system overhead, excessive CPU usage, and inadequate disk space. It is required that trace level be set to 4 to capture bind values, along with the execution plans.

For production systems running Oracle Database 10g Release 1, use the DBMS_MONITOR.SESSION_TRACE_ENABLE procedure to enable SQL Trace transparently in another session. You should also enable binds explicitly by setting the binds procedure parameter to TRUE (its default value is FALSE).

After enabling SQL Trace, identify the SQL trace files containing statistics for a representative set of SQL statements that you want to use with SQL Performance Analyzer. You can then copy the SQL trace files to the SQL Performance Analyzer system. Once the SQL workload is captured in the SQL trace files, disable SQL Trace on the production system.

See Also:

- Oracle Database SQL Tuning Guide for additional considerations when using SQL Trace, such as setting initialization parameters to manage SQL trace files

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_MONITOR package

Creating a Mapping Table

To convert the user and object identifier numbers stored in the SQL trace files to their respective names, you need to provide a table that specifies each mapping. The SQL Performance Analyzer system will read this mapping table when converting the trace files into a SQL tuning set.

To create a mapping table:

- Run the following SQL statements on the production database:

CREATE TABLE mapping AS
SELECT object_id id, owner, SUBSTR(object_name, 1, 30) name FROM dba_objects
WHERE object_type NOT IN ('CONSUMER GROUP', 'EVALUATION CONTEXT', 'FUNCTION',
'INDEXTYPE', 'JAVA CLASS', 'JAVA DATA',
'JAVA RESOURCE', 'LIBRARY', 'LOB', 'OPERATOR',
'PACKAGE', 'PACKAGE BODY', 'PROCEDURE', 'QUEUE',
'RESOURCE PLAN', 'SYNONYM', 'TRIGGER', 'TYPE',
'TYPE BODY')
UNION ALL
SELECT user_id id, username owner, null name FROM dba_users;

Once the mapping table is created, you can use Data Pump to transport it to the SQL Performance Analyzer system.

See Also:

- Oracle Database Utilities for information about using Data Pump

Building a SQL Tuning Set

Once the SQL trace files and mapping table are moved to the SQL Performance Analyzer system, you can build a SQL tuning set using the DBMS_SQLTUNE package.

To build a SQL tuning set:

1. Copy the SQL trace files to a directory on the SQL Performance Analyzer system.

2. Create a directory object for this directory.

3. Use the DBMS_SQLTUNE.SELECT_SQL_TRACE function to read the SQL statements from the SQL trace files.
For each SQL statement, only information for a single execution is collected. The execution frequency of each SQL statement is not captured. Therefore, when performing a comparison analysis for a production system running Oracle Database 10g Release 1 and older releases, you should ignore the workload-level statistics in the SQL Performance Analyzer report and only evaluate performance changes on an execution level.

The following example reads the contents of SQL trace files stored in the sql_trace_prod directory object and loads them into a SQL tuning set.

DECLARE
cur sys_refcursor;
BEGIN
DBMS_SQLTUNE.CREATE_SQLSET('my_sts_9i');
OPEN cur FOR
SELECT VALUE (P)
FROM table(DBMS_SQLTUNE.SELECT_SQL_TRACE('sql_trace_prod', '%ora%')) P;
DBMS_SQLTUNE.LOAD_SQLSET('my_sts_9i', cur);
CLOSE cur;
END;
/

The syntax for the SELECT_SQL_TRACE function is as follows:

DBMS_SQLTUNE.SELECT_SQL_TRACE (
directory              IN VARCHAR2,
file_name              IN VARCHAR2 := NULL,
mapping_table_name     IN VARCHAR2 := NULL,
mapping_table_owner    IN VARCHAR2 := NULL,
select_mode            IN POSITIVE := SINGLE_EXECUTION,
options                IN BINARY_INTEGER := LIMITED_COMMAND_TYPE,
pattern_start          IN VARCHAR2 := NULL,
parttern_end           IN VARCHAR2 := NULL,
result_limit           IN POSITIVE := NULL)
RETURN sys.sqlset PIPELINED;

Table 8-1 describes the available parameters for the SELECT_SQL_TRACE function.

Table 8-1 DBMS_SQLTUNE.SELECT_SQL_TRACE Function Parameters

Parameter

Description

directory

Specifies the directory object pointing to the directory where the SQL trace files are stored.

file_name

Specifies all or part of the name of the SQL trace files to process. If unspecified, the current or most recent trace file in the specified directory will be used. % wildcards are supported for matching trace file names.

mapping_table_name

Specifies the name of the mapping table. If set to the default value of NULL, mappings from the current database will be used. Note that the mapping table name is not case-sensitive.

mapping_table_owner

Specifies the schema where the mapping table resides. If set to NULL, the current schema will be used.

select_mode

Specifies the mode for selecting SQL statements from the trace files. The default value is SINGLE_EXECUTION. In this mode, only statistics for a single execution per SQL statement will be loaded into the SQL tuning set. The statistics are not cumulative, as is the case with other SQL tuning set data source table functions.

options

Specifies the options for the operation. The default value is LIMITED_COMMAND_TYPE, only SQL types that are meaningful to SQL Performance Analyzer (such as SELECT, INSERT, UPDATE, and DELETE) are returned from the SQL trace files.

pattern_start

Specifies the opening delimiting pattern of the trace file sections to consider. This parameter is currently not used.

pattern_end

Specifies the closing delimiting pattern of the trace file sections to process. This parameter is currently not used.

result_limit

Specifies the top SQL from the (filtered) source. The default value is 2^31, which represents unlimited.

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_SQLTUNE package

Testing Database Upgrades from Oracle9i Database and Oracle Database 10g Release 1

Once the SQL tuning set is built, you can use SQL Performance Analyzer to build a pre-upgrade SQL trial from the execution plans and run-time statistics in the SQL tuning set. After the pre-upgrade SQL trial is built, perform a test execute or generate plans of SQL statements in the SQL tuning set on the test system to build a post-upgrade SQL trial. SQL Performance Analyzer test executes the SQL statements using a public database link that you specify by connecting to the test system remotely and generating the execution plans and statistics for the SQL trial. The database link should exist on the SQL Performance Analyzer system and connect to a remote user with privileges to execute the SQL tuning set on the test system.

You can run SQL Performance Analyzer to test a database upgrade from Oracle9i Database or Oracle Database 10g Release 1 using Oracle Enterprise Manager or APIs, as described in the following sections:

- Testing Database Upgrades from Releases 9.x and 10.1 Using Cloud Control

- Testing Database Upgrades from Releases 9.x and 10.1 Using APIs

Testing Database Upgrades from Releases 9.x and 10.1 Using Cloud Control

To test a database upgrade from Oracle9i Database or Oracle Database 10g Release 1 using SQL Performance Analyzer:

1. From the Performance menu, select SQL, then SQL Performance Analyzer.
If the Database Login page appears, then log in as a user with administrator privileges.

The SQL Performance Analyzer page appears.

2. Under SQL Performance Analyzer Workflows, click Upgrade from 9i or 10.1.
The Upgrade from 9i or 10.1 page appears.

3. Under Task Information:

a. In the Task Name field, enter the name of the task.

b. In the SQL Tuning Set field, enter the name of the SQL tuning set that was built.
Alternatively, click the search icon to search for the SQL tuning set using the Search and Select: SQL Tuning Set window.

The selected SQL tuning set now appears in the SQL Tuning Set field.

c. In the Description field, optionally enter a description of the task.

4. In the Creation Method field, select:

- Execute SQLs to generate both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements remotely on the test system over a public database link.

- Generate Plans to create execution plans remotely on the test system over a public database link without actually running the SQL statements.

5. In the Per-SQL Time Limit list, determine the time limit for SQL execution during the trial by performing one of the following actions:

- Select 5 minutes.
The execution will run each SQL statement in the SQL tuning set up to 5 minutes and gather performance data.

- Select Unlimited.
The execution will run each SQL statement in the SQL tuning set to completion and gather performance data. Collecting execution statistics provides greater accuracy in the performance analysis but takes a longer time. Using this setting is not recommended because the task may be stalled by one SQL statement for a prolonged time period.

- Select Customize and enter the specified number of seconds, minutes, or hours.

6. In the Database Link field, enter the global name of a public database link connecting to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the test system.
Alternatively, click the search icon to search for and select a database link, or click Create Database Link to create a database link using the Create Database Link page.

7. In the Comparison Metric list, select the comparison metric to use for the comparison analysis:

- Elapsed Time

- CPU Time

- User I/O Time

- Buffer Gets

- Physical I/O

- Optimizer Cost

- I/O Interconnect Bytes

Optimizer Cost is the only comparison metric available if you generated execution plans only in the SQL trials.

To perform the comparison analysis by using more than one comparison metric, perform separate comparison analyses by repeating this procedure with different metrics.

8. Under Schedule:

a. In the Time Zone list, select your time zone code.

b. Select Immediately to start the task now, or Later to schedule the task to start at a time specified using the Date and Time fields.

9. Click Submit.
The SQL Performance Analyzer page appears.

In the SQL Performance Analyzer Tasks section, the status of this task is displayed. To refresh the status icon, click Refresh. After the task completes, the Status field changes to Completed.

10. Under SQL Performance Analyzer Tasks, select the task and click the link in the Name column.
The SQL Performance Analyzer Task page appears.

This page contains the following sections:

- SQL Tuning Set
This section summarizes information about the SQL tuning set, including its name, owner, description, and the number of SQL statements it contains.

- SQL Trials
This section includes a table that lists the SQL trials used in the SQL Performance Analyzer task.

- SQL Trial Comparisons
This section contains a table that lists the results of the SQL trial comparisons

11. Click the icon in the Comparison Report column.
The SQL Performance Analyzer Task Result page appears.

12. Review the results of the performance analysis, as described in "Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager".
If regressed SQL statements are found following the database upgrade, tune them as described in "Tuning Regressed SQL Statements After Testing a Database Upgrade".

Testing Database Upgrades from Releases 9.x and 10.1 Using APIs

This section describes how to test database upgrades from Oracle Database releases 9.x and 10.1 using APIs.

To test a database upgrade from releases 9.x and 10.1:

1. On the system running SQL Performance Analyzer, create an analysis task.

2. Build the pre-upgrade SQL trial from the execution plans and run-time statistics in the SQL tuning set by calling the EXECUTE_ANALYSIS_TASK procedure using the following parameters:

- Set the task_name parameter to the name of the SQL Performance Analyzer task that you want to execute.

- Set the execution_type parameter to CONVERT SQLSET to direct SQL Performance Analyzer to treat the statistics in the SQL tuning set as a trial execution.

- Specify a name to identify the execution using the execution_name parameter. If not specified, then SQL Performance Analyzer automatically generates a name for the task execution.

The following example executes the SQL Performance Analyzer task named my_spa_task as a trial execution:

EXEC DBMS_SQLPA.EXECUTE_ANALYSIS_TASK(task_name => 'my_spa_task', -
execution_type => 'CONVERT SQLSET', -
execution_name => 'my_trial_9i');

3. Build the post-upgrade SQL trial by performing an explain plan or test execute using the EXECUTE_ANALYSIS_TASK procedure:

- Set the execution_type parameter to EXPLAIN PLAN or TEST EXECUTE:

- If you choose to use EXPLAIN PLAN, only execution plans will be generated. Subsequent comparisons will only be able to yield a list of changed plans without making any conclusions about performance changes.

- If you choose to use TEST EXECUTE, the SQL workload will be executed to completion. This effectively builds the post-upgrade SQL trial using the statistics and execution plans generated from the test system. Using TEST EXECUTE is recommended to capture the SQL execution plans and performance data at the source, thereby resulting in a more accurate analysis.

- Set the DATABASE_LINK task parameter to the global name of a public database link connecting to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the test system.

The following example performs a test execute of the SQL statements remotely over a database link:

EXEC DBMS_SQLPA.EXECUTE_ANALYSIS_TASK(task_name => 'my_spa_task', -
execution_type => 'TEST EXECUTE', -
execution_name => 'my_remote_trial_10g', -
execution_params => dbms_advisor.arglist('database_link',
'LINK.A.B.C.BIZ.COM'));

See Also:

- "Creating an Analysis Task Using APIs"

- "Creating a Pre-Change SQL Trial Using APIs"

- "Creating a Post-Change SQL Trial Using APIs"

- Oracle Database PL/SQL Packages and Types Reference to learn about the DBMS_SQLPA.EXECUTE_ANALYSIS_TASK function

Upgrading from Oracle Database 10g Release 2 and Newer Releases

You can use SQL Performance Analyzer to test the impact on SQL response time of a database upgrade from Oracle Database 10g Release 2 or a newer release to any later release by capturing a SQL tuning set on the production system, then executing it twice remotely over a database link on a test system—first to create a pre-change SQL trial, then again to create a post-change SQL trial.

Before the database upgrade can be tested, ensure that the following conditions are met:

- The production system which you are upgrading from is running Oracle Database 10g Release 2 or a newer release.

- Initially, the test system should also be running the same release of Oracle Database.

- The test system must contain an exact copy of the production data found on the production system.

- The hardware configuration must be as similar to the production system as possible.

You will also need to set up a separate SQL Performance Analyzer system running Oracle Database 11g Release 2. You will be using this system to run SQL Performance Analyzer. Neither your production data or schema need to be available on this system, since the SQL tuning set will be built using statistics stored in the SQL trace files from the production system. SQL Performance Analyzer tasks will be executed remotely on the test system to generate the execution plan and statistics for the SQL trial over a database link that you specify. The database link must be a public database link that connects to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the test system. You should also drop any existing PLAN_TABLE from the user's schema on the test system.

Once the upgrade environment is configured as described, perform the steps as described in the following procedure to use SQL Performance Analyzer in a database upgrade from Oracle Database 10g Release 2 or a newer release to any later release.

1. On the production system, capture the SQL workload that you intend to analyze and store it in a SQL tuning set, as described in "Capturing the SQL Workload".

2. Set up the test system so that it matches the production environment as closely as possible, as described in "Setting Up the Test System".

3. Transport the SQL tuning set to the SQL Performance Analyzer system.

For information about transporting SQL tuning sets using:

- Oracle Enterprise Manager, see Oracle Database 2 Day + Performance Tuning Guide

- APIs, see Oracle Database SQL Tuning Guide

4. On the SQL Performance Analyzer system, create a SQL Performance Analyzer task using the SQL tuning set as its input source.

Remotely test execute the SQL statements in the SQL tuning set on the test system over a database link to build a pre-upgrade SQL trial that will be used as a baseline for comparison, as described in "Testing Database Upgrades from Oracle Database 10g Release 2 and Newer Releases".

5. Upgrade the test system.

6. Remotely test execute the SQL statements a second time on the upgraded test system over a database link to build a post-upgrade SQL trial, as described in "Testing Database Upgrades from Oracle Database 10g Release 2 and Newer Releases".

7. Compare SQL performance and fix regressed SQL.

SQL Performance Analyzer compares the performance of SQL statements read from the SQL tuning set during the pre-upgrade SQL trial to those captured from the remote test execution during the post-upgrade SQL trial. A report is produced to identify any changes in execution plans or performance of the SQL statements.

If the report reveals any regressed SQL statements, you can make further changes to fix the regressed SQL, as described in "Tuning Regressed SQL Statements After Testing a Database Upgrade".

Repeat the process of executing the SQL tuning set and comparing its performance to a previous execution to test any changes made until you are satisfied with the outcome of the analysis.

Testing Database Upgrades from Oracle Database 10g Release 2 and Newer Releases

Once the SQL tuning set is transported to the SQL Performance Analyzer system, you can use SQL Performance Analyzer to build a pre-upgrade SQL trial by executing or generating plans of SQL statements in the SQL tuning set on the test system. SQL Performance Analyzer test executes the SQL statements using a database link that you specify by connecting to the test system remotely and generating the execution plans and statistics for the SQL trial. The database link should exist on the SQL Performance Analyzer system and connect to a remote user with privileges to execute the SQL tuning set on the test system.

After the pre-upgrade SQL trial is built, you need to upgrade the test system. Once the database has been upgraded, SQL Performance Analyzer will need to execute or generate plans of SQL statements in the SQL tuning set a second time on the upgraded test system to build a post-upgrade SQL trial. Alternatively, if hardware resources are available, you can use another upgraded test system to execute the second remote SQL trial. This method can be useful in helping you investigate issues identified by SQL Performance Analyzer.

You can run SQL Performance Analyzer to test a database upgrade from Oracle Database 10g Release 2 or a newer release using Oracle Enterprise Manager or APIs, as described in the following sections:

- Testing Database Upgrades from Releases 10.2 and Higher Using Cloud Control

- Testing Database Upgrades from Releases 10.2 and Higher Using APIs

Testing Database Upgrades from Releases 10.2 and Higher Using Cloud Control

To test a database upgrade from Oracle Database 10g Release 2 or a newer release using SQL Performance Analyzer:

1. From the Performance menu, select SQL, then SQL Performance Analyzer.
If the Database Login page appears, then log in as a user with administrator privileges.

The SQL Performance Analyzer page appears.

2. Under SQL Performance Analyzer Workflows, click Upgrade from 10.2 or 11g.
The Upgrade from 10.2 or 11g page appears.

3. Under Task Information:

a. In the Task Name field, enter the name of the task.

b. In the SQL Tuning Set field, enter the name of the SQL tuning set that was built.
Alternatively, click the search icon to search for the SQL tuning set using the Search and Select: SQL Tuning Set window.

The selected SQL tuning set now appears in the SQL Tuning Set field.

c. In the Description field, optionally enter a description of the task.

4. In the Creation Method field, select:

- Execute SQLs to generate both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements remotely on the test system over a public database link.

- Generate Plans to create execution plans remotely on the test system over a public database link without actually running the SQL statements.

5. In the Per-SQL Time Limit list, determine the time limit for SQL execution during the trial by performing one of the following actions:

- Select 5 minutes.
The execution will run each SQL statement in the SQL tuning set up to 5 minutes and gather performance data.

- Select Unlimited.
The execution will run each SQL statement in the SQL tuning set to completion and gather performance data. Collecting execution statistics provides greater accuracy in the performance analysis but takes a longer time. Using this setting is not recommended because the task may be stalled by one SQL statement for a prolonged time period.

- Select Customize and enter the specified number of seconds, minutes, or hours.

6. In the Database Link field, enter the global name of a public database link connecting to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the pre-upgrade system.
Alternatively, click the search icon to search for and select a database link, or click Create Database Link to create a database link using the Create Database Link page.

7. Under Post-upgrade Trial:

a. Select Use the same system as in the pre-upgrade trial to use the same system for executing both the pre-upgrade and post-upgrade trials.
Oracle recommends using this option to avoid possible errors due to different system configurations. When using this option, you will need to upgrade the test database to the higher database version before the post-upgrade trial is executed.

b. In the Database Link field, enter the global name of a public database link connecting to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the post-upgrade system.

8. In the Comparison Metric list, select the comparison metric to use for the comparison analysis:

- Elapsed Time

- CPU Time

- User I/O Time

- Buffer Gets

- Physical I/O

- Optimizer Cost

- I/O Interconnect Bytes

Optimizer Cost is the only comparison metric available if you generated execution plans only in the SQL trials.

To perform the comparison analysis by using more than one comparison metric, perform separate comparison analyses by repeating this procedure with different metrics.

9. Under Schedule:

a. In the Time Zone list, select your time zone code.

b. Select Immediately to start the task now, or Later to schedule the task to start at a time specified using the Date and Time fields.

10. Click Submit.
The SQL Performance Analyzer page appears.

In the SQL Performance Analyzer Tasks section, the status of this task is displayed. To refresh the status icon, click Refresh.

If you are using the same system to execute both the pre-upgrade and post-upgrade trials, you will need to upgrade the database after the pre-upgrade trial step is completed. After the database is upgraded, the post-upgrade trial can be executed. After the task completes, the Status field changes to Completed.

11. Under SQL Performance Analyzer Tasks, select the task and click the link in the Name column.
The SQL Performance Analyzer Task page appears.

This page contains the following sections:

- SQL Tuning Set
This section summarizes information about the SQL tuning set, including its name, owner, description, and the number of SQL statements it contains.

- SQL Trials
This section includes a table that lists the SQL trials used in the SQL Performance Analyzer task.

- SQL Trial Comparisons
This section contains a table that lists the results of the SQL trial comparisons

12. Click the icon in the Comparison Report column.
The SQL Performance Analyzer Task Result page appears.

13. Review the results of the performance analysis, as described in "Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager".
If regressed SQL statements are found following the database upgrade, tune them as described in "Tuning Regressed SQL Statements After Testing a Database Upgrade".

Testing Database Upgrades from Releases 10.2 and Higher Using APIs

This section describes how to test database upgrades from Oracle Database releases 10.2 and higher using APIs.

To test a database upgrade from releases 10.2 and higher:

1. On the system running SQL Performance Analyzer, create an analysis task.

2. Build the pre-upgrade SQL trial by performing an explain plan or test execute of SQL statements in the SQL tuning set.
Call the EXECUTE_ANALYSIS_TASK procedure using the following parameters:

- Set the task_name parameter to the name of the SQL Performance Analyzer task that you want to execute.

- Set the execution_type parameter to EXPLAIN PLAN or TEST EXECUTE:

- If you choose to use EXPLAIN PLAN, only execution plans will be generated. Subsequent comparisons will only be able to yield a list of changed plans without making any conclusions about performance changes.

- If you choose to use TEST EXECUTE, the SQL workload will be executed to completion. This effectively builds the pre-upgrade SQL trial using the statistics and execution plans generated from the test system. Using TEST EXECUTE is recommended to capture the SQL execution plans and performance data at the source, thereby resulting in a more accurate analysis.

- Specify a name to identify the execution using the execution_name parameter. If not specified, then SQL Performance Analyzer automatically generates a name for the task execution.

- Set the DATABASE_LINK task parameter to the global name of a public database link connecting to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the test system.

The following example executes the SQL Performance Analyzer task named my_spa_task and performs a test execute of the SQL statements remotely over a database link:

EXEC DBMS_SQLPA.EXECUTE_ANALYSIS_TASK(task_name => 'my_spa_task', -
execution_type => 'TEST EXECUTE', -
execution_name => 'my_remote_trial_10g', -
execution_params => dbms_advisor.arglist('database_link',
'LINK.A.B.C.BIZ.COM'));

3. Build the post-upgrade SQL trial by performing an explain plan or test execute using the EXECUTE_ANALYSIS_TASK procedure:

- Set the execution_type parameter to EXPLAIN PLAN or TEST EXECUTE:

- If you choose to use EXPLAIN PLAN, only execution plans will be generated. Subsequent comparisons will only be able to yield a list of changed plans without making any conclusions about performance changes.

- If you choose to use TEST EXECUTE, the SQL workload will be executed to completion. This effectively builds the post-upgrade SQL trial using the statistics and execution plans generated from the test system. Using TEST EXECUTE is recommended to capture the SQL execution plans and performance data at the source, thereby resulting in a more accurate analysis.

- Set the DATABASE_LINK task parameter to the global name of a public database link connecting to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the test system.

The following example performs a test execute of the SQL statements remotely over a database link:

EXEC DBMS_SQLPA.EXECUTE_ANALYSIS_TASK(task_name => 'my_spa_task', -
execution_type => 'TEST EXECUTE', -
execution_name => 'my_remote_trial_12c', -
execution_params => dbms_advisor.arglist('database_link',
'LINK.A.B.C.BIZ.COM'));

See Also:

- "Creating an Analysis Task Using APIs"

- "Creating a Pre-Change SQL Trial Using APIs"

- "Creating a Post-Change SQL Trial Using APIs"

- Oracle Database PL/SQL Packages and Types Reference to learn about the DBMS_SQLPA.EXECUTE_ANALYSIS_TASK function

- Oracle Database PL/SQL Packages and Types Reference to learn about the DBMS_SQLPA.EXECUTE_ANALYSIS_TASK function

Tuning Regressed SQL Statements After Testing a Database Upgrade

In some cases, SQL Performance Analyzer may identify SQL statements whose performance regressed after you upgrade the database on the test system.

You can tune the regressed SQL statements by using the SQL Tuning Advisor or SQL plan baselines, as described in Comparing SQL Trials . This involves using APIs to build a subset of a SQL tuning set with only the regressed SQL statements, transport this subset of regressed SQL statements to the remote database, and running the SQL Tuning Advisor on the remote database.

Oracle Enterprise Manager does not provide support for fixing regressions after running SQL Performance Analyzer involving one or more remote SQL trials. For more information, see "Tuning Regressed SQL Statements From a Remote SQL Trial Using APIs".

If you are upgrading from Oracle Database 10g Release 2 and newer releases, you can also create SQL plan baselines to instruct the optimizer to select existing execution plans in the future. For more information, see "Creating SQL Plan Baselines Using APIs".

Part II Database Replay

Database Replay enables you to replay a full production workload on a test system to assess the overall impact of system changes.

Part II covers Database Replay and contains the following chapters:

- Introduction to Database Replay

- Capturing a Database Workload

- Preprocessing a Database Workload

- Replaying a Database Workload

- Analyzing Captured and Replayed Workloads

- Using Workload Intelligence

- Using Consolidated Database Replay

- Using Workload Scale-Up

9 Introduction to Database Replay

You can use Database Replay to capture a workload on the production system and replay it on a test system with the exact timing, concurrency, and transaction characteristics of the original workload. This enables you to test the effects of a system change without affecting the production system.

Database Replay supports workload capture on a system running Oracle Database 10g Release 2 and newer releases. In order to capture a workload on a system running Oracle Database 10g Release 2, the database version must be 10.2.0.4 or higher. Workload replay is only supported on systems running Oracle Database 11g Release 1 and newer releases.

Note:

To use the workload capture feature on a system running Oracle9i Database or an earlier version of Oracle Database 10g, refer to My Oracle Support note ID 560977.1 for information about the required patches, or contact Oracle Support for more information.

Analyzing the effect of system changes using Database Replay involves the following steps, as illustrated in Figure 9-1:

Figure 9-1 Database Replay Workflow

1. On the production system, capture the workload into capture files, as described in "Workload Capture".

2. Copy the capture files to the test system and preprocess them, as described in "Workload Preprocessing".

3. On the test system, replay the preprocessed files, as described in "Workload Replay".

4. Using the reports generated by Database Replay, perform detailed analysis of both the workload capture and workload replay, as described in "Analysis and Reporting".

Workload Capture

The first step in using Database Replay is to capture the production workload. Capturing a workload involves recording all requests made by external clients to Oracle Database.

When workload capture is enabled, all external client requests directed to Oracle Database are tracked and stored in binary files—called capture files—on the file system. You can specify the location where the capture files will be stored. Once workload capture begins, all external database calls are written to the capture files. The capture files contain all relevant information about the client request, such as SQL text, bind values, and transaction information. Background activities and database scheduler jobs are not captured. These capture files are platform independent and can be transported to another system.

See Also:

- Capturing a Database Workload for information about how to capture a workload on the production system

Workload Preprocessing

Once the workload has been captured, the information in the capture files must be preprocessed. Preprocessing creates all necessary metadata needed for replaying the workload. This must be done once for every captured workload before they can be replayed. After the captured workload is preprocessed, it can be replayed repeatedly on a replay system running the same version of Oracle Database. Typically, the capture files should be copied to a test system for preprocessing. As workload preprocessing can be time consuming and resource intensive, it is recommended that this step be performed on the test system where the workload will be replayed.

See Also:

- Preprocessing a Database Workload for information about how to preprocess a captured workload

Workload Replay

After a captured workload has been preprocessed, it can be replayed on a test system. During the workload replay phase, Oracle Database performs the actions recorded during the workload capture phase on the test system by re-creating all captured external client requests with the same timing, concurrency, and transaction dependencies of the production system.

Database Replay uses a client program called the replay client to re-create all external client requests recorded during workload capture. Depending on the captured workload, you may need one or more replay clients to properly replay the workload. A calibration tool is provided to help determine the number of replay clients needed for a particular workload. Because the entire workload is replayed—including DML and SQL queries—the data in the replay system should be as logically similar to the data in the capture system as possible. This will minimize replay divergence and enable a more reliable analysis of the replay.

See Also:

- Replaying a Database Workload for information about how to replay a preprocessed workload on the test system

Analysis and Reporting

Once the workload is replayed, in-depth reporting is provided for you to perform detailed analysis of both workload capture and replay.

The workload capture report and workload replay report provide basic information about the workload capture and replay, such as errors encountered during replay and data divergence in rows returned by DML or SQL queries. A comparison of several statistics—such as database time, average active sessions, and user calls—between the workload capture and the workload replay is also provided.

The replay compare period report can be used to perform a high-level comparison of one workload replay to its capture or to another replay of the same capture. A divergence summary with an analysis of whether any data divergence occurred and if there were any significant performance changes is also provided. Furthermore, Automatic Database Diagnostic Monitor (ADDM) findings are incorporated into these reports.

For advanced analysis, Automatic Workload Repository (AWR) reports are available to enable detailed comparison of performance statistics between the workload capture and the workload replay. The information available in these reports is very detailed, and some differences between the workload capture and replay can be expected. Furthermore, Workload Intelligence operates on data recorded during a workload capture to create a model that describes the workload. This model can be used to identify significant patterns in templates that are executed as part of the workload. For each pattern, you can view important statistics, such as the number of executions of a given pattern and the database time consumed by the pattern during its execution.

The SQL Performance Analyzer report can be used to compare a SQL tuning set from a workload capture to another SQL tuning set from a workload replay, or two SQL tuning sets from two workload replays. Comparing SQL tuning sets with Database Replay provides more information than SQL Performance Analyzer test-execute because it considers and shows all execution plans for each SQL statement, while SQL Performance Analyzer test-execute generates only one execution plan per SQL statement for each SQL trial. Moreover, the SQL statements are executed in a more authentic environment because Database Replay captures all bind values and reproduces dynamic session state such as PL/SQL package state more accurately. It is recommended that you run SQL Performance Analyzer test-execute first as a sanity test to ensure SQL statements have not regressed and the test system is set up properly before using Database Replay to perform load and currency testing.

Besides using replay divergence information to analyze replay characteristics of a given system change, you should also use an application-level validation procedure to assess the system change. Consider developing a script to assess the overall success of the replay. For example, if 10,000 orders are processed during workload capture, you should validate that a similar number of orders are also processed during replay.

After the replay analysis is complete, you can restore the database to its original state at the time of workload capture and repeat workload replay to test other changes to the system.

See Also:

- Analyzing Captured and Replayed Workloads for information about how to analyze data and performance divergence using Database Replay reports

10 Capturing a Database Workload

This chapter describes how to capture a database workload on the production system. The first step in using Database Replay is to capture the production workload. For more information about how capturing a database workload fits within the Database Replay architecture, see "Workload Capture".

This chapter contains the following sections:

- Prerequisites for Capturing a Database Workload

- Setting Up the Capture Directory

- Workload Capture Options

- Workload Capture Restrictions

- Enabling and Disabling the Workload Capture Feature

- Enterprise Manager Privileges and Roles

- Capturing a Database Workload Using Enterprise Manager

- Capturing Workloads from Multiple Databases Concurrently

- Monitoring a Workload Capture Using Enterprise Manager

- Importing a Workload External to Enterprise Manager

- Creating Subsets from an Existing Workload

- Copying or Moving a Workload to a New Location

- Capturing a Database Workload Using APIs

- Monitoring Workload Capture Using Views

Prerequisites for Capturing a Database Workload

Before starting a workload capture, you should have a strategy in place to restore the database on the test system. Before a workload can be replayed, the logical state of the application data on the replay system should be similar to that of the capture system when replay begins. To accomplish this, consider using one of the following methods:

- Recovery Manager (RMAN) DUPLICATE command

- Snapshot standby

- Data Pump Import and Export

This will allow you to restore the database on the replay system to the application state as of the workload capture start time.

See Also:

- Oracle Database Backup and Recovery User's Guide for information about duplicating a database using RMAN

- Oracle Data Guard Concepts and Administration for information about managing snapshot standby databases

- Oracle Database Utilities for information about using Data Pump

Setting Up the Capture Directory

Determine the location and set up a directory where the captured workload will be stored. Before starting the workload capture, ensure that the directory is empty and has ample disk space to store the workload. If the directory runs out of disk space during a workload capture, the capture will stop. To estimate the amount of disk space that is required, you can run a test capture on your workload for a short duration (such as a few minutes) to extrapolate how much space you will need for a full capture. To avoid potential performance issues, you should also ensure that the target replay directory is mounted on a separate file system.

For Oracle RAC, consider using a shared file system. Alternatively, you can set up one capture directory path that resolves to separate physical directories on each instance, but you will need to consolidate the files created in each of these directories into a single directory. For captures on an Oracle RAC database, Enterprise Manager only supports Oracle RAC configured with a shared file system. The entire content of the local capture directories on each instance (not only the capture files) must be copied to the shared directory before it can be used for preprocessing or data masking. For example, assume that you are:

- Running an Oracle RAC environment in Linux with two database instances named host1 and host2

- Using a capture directory object named CAPDIR that resolves to /$ORACLE_HOME/rdbms/capture on both instances

- Using a shared directory that resides in /nfs/rac_capture

You will need to login into each host and run the following command:

cp -r /$ORACLE_HOME/rdbms/capture/* /nfs/rac_capture

After this is done for both instances, the /nfs/rac_capture shared directory is ready to be preprocessed or masked.

Workload Capture Options

Proper planning before workload capture is required to ensure that the capture will be accurate and useful when replayed in another environment.

Before capturing a database workload, carefully consider the following options:

- Restarting the Database

- Using Filters with Workload Capture

Restarting the Database

While this step is not required, Oracle recommends that the database be restarted before capturing the workload to ensure that ongoing and dependent transactions are allowed to be completed or rolled back before the capture begins. If the database is not restarted before the capture begins, transactions that are in progress or have yet to be committed will not be fully captured in the workload. Ongoing transactions will thus not be replayed properly, because only the part of the transaction whose calls were captured will be replayed. This may result in undesired replay divergence when the workload is replayed. Any subsequent transactions with dependencies on the incomplete transactions may also generate errors during replay. On a busy system, it is normal to see some replay divergence, but the replay can still be used to perform meaningful analysis of a system change if the diverged calls do not make up a significant portion of the replay in terms of DB time and other such key attributes.

Before restarting the database, determine an appropriate time to shut down the production database before the workload capture when it is the least disruptive. For example, you may want to capture a workload that begins at 8:00 a.m. However, to avoid service interruption during normal business hours, you may not want to restart the database during this time. In this case, you should consider starting the workload capture at an earlier time, so that the database can be restarted at a time that is less disruptive.

Once the database is restarted, it is important to start the workload capture before any user sessions reconnect and start issuing any workload. Otherwise, transactions performed by these user sessions will not be replayed properly in subsequent database replays, because only the part of the transaction whose calls were executed after the workload capture is started will be replayed. To avoid this problem, consider restarting the database in RESTRICTED mode using STARTUP RESTRICT, which will only allow the SYS user to login and start the workload capture. By default, once the workload capture begins, any database instance that are in RESTRICTED mode will automatically switch to UNRESTRICTED mode, and normal operations can continue while the workload is being captured.

Only one workload capture can be performed at any given time. If you have a Oracle Real Application Clusters (Oracle RAC) configuration, workload capture is performed for the entire database. Once you enable capture for one of the Oracle RAC nodes, workload capture is started on all database instances (the workload capture process is Oracle RAC aware). Although it is not required, restarting all instances in a Oracle RAC configuration before workload capture is recommended to avoid capturing ongoing transactions.

To restart all instances in a Oracle RAC configuration before workload capture:

1. Shut down all the instances.

2. Restart all the instances.

3. Start workload capture.

4. Connect the application and start the user workload.

See Also:

- Oracle Database Administrator's Guide for information about restricting access to an instance at startup

Using Filters with Workload Capture

By default, all user sessions are recorded during workload capture. You can use workload filters to specify which user sessions to include in or exclude from the workload during workload capture. There are two types of workload filters: inclusion filters and exclusion filters. You can use either inclusion filters or exclusion filters in a workload capture, but not both.

Inclusion filters enable you to specify user sessions that will be captured in the workload. This is useful if you want to capture only a subset of the database workload.

Exclusion filters enable you to specify user sessions that will not be captured in the workload. This is useful if you want to filter out session types that do not need to captured in the workload, such as those that monitor the infrastructure—like Oracle Enterprise Manager (EM) or Statspack—or other such processes that are already running on the test system. For example, if the system where the workload will be replayed is running EM, replaying captured EM sessions on the system will result in duplication of workload. In this case, you may want to use exclusion filters to filter out EM sessions.

Workload Capture Restrictions

Certain types of user sessions and client requests may sometimes be captured in a workload, but they are not supported by Database Replay. Capturing these session and request types in a workload may result in errors during workload replay.

The following types of user sessions and client requests are not supported by Database Replay:

- Direct path load of data from external files using utilities such as SQL*Loader

- Non-PL/SQL based Advanced Queuing (AQ)

- Flashback queries

- Oracle Call Interface (OCI) based object navigations

- Non SQL-based object access

- Distributed transactions
Any distributed transactions that are captured will be replayed as local transactions.

- XA transactions
XA transactions are not captured or replayed. All local transactions are captured.

- JAVA_XA transactions
If the workload uses the JAVA_XA package, JAVA_XA function and procedure calls are captured as normal PL/SQL workload. To avoid problems during workload replay, consider dropping the JAVA_XA package on the replay system to enable the replay to complete successfully.

- Database Resident Connection Pooling (DRCP)

- Workloads using OUT binds

- Multi-threaded Server (MTS) and shared server sessions with synchronization mode set to OBJECT_ID

- Migrated sessions
The workload is captured for migrated sessions. However, user logins or session migration operations are not captured. Without a valid user login or session migration, the replay may cause errors because the workload may be replayed by a wrong user.

Typically, Database Replay refrains from capturing these types of non-supported user sessions and client requests. Even when they are captured, Database Replay will not replay them. Therefore, it is usually not necessary to manually filter out non-supported user sessions and client requests. In cases where they are captured and found to cause errors during replay, consider using workload capture filters to exclude them from the workload.

See Also:

- "Using Filters with Workload Capture" for information about using workload capture filters

- "Using Filters with Workload Replay" for information about using workload replay filters

Enabling and Disabling the Workload Capture Feature

Database Replay supports capturing a database workload on a system running Oracle Database 10g Release 2 that can be used to test database upgrades to Oracle Database 11g and subsequent releases. By default, the workload capture feature is not enabled in Oracle Database 10g Release 2 (10.2). You can enable or disable this feature by specifying the PRE_11G_ENABLE_CAPTURE initialization parameter.

Note:

It is only necessary to enable the workload capture feature if you are capturing a database workload on a system running Oracle Database 10g Release 2.

If you are capturing a database workload on a system running Oracle Database 11g Release 1 or a later release, it is not necessary to enable the workload capture feature because it is enabled by default. Furthermore, the PRE_11G_ENABLE_CAPTURE initialization parameter is only valid with Oracle Database 10g Release 2 (10.2) and cannot be used with subsequent releases.

To enable the workload capture feature on a system running Oracle Database 10g Release 2, run the wrrenbl.sql script at the SQL prompt:

@$ORACLE_HOME/rdbms/admin/wrrenbl.sql

The wrrenbl.sql script calls the ALTER SYSTEM SQL statement to set the PRE_11G_ENABLE_CAPTURE initialization parameter to TRUE. If a server parameter file (spfile) is being used, the PRE_11G_ENABLE_CAPTURE initialization parameter will be modified for the currently running instance and recorded in the spfile, so that the new setting will persist when the database is restarted. If a spfile is not being used, the PRE_11G_ENABLE_CAPTURE initialization parameter will only be modified for the currently running instance, and the new setting will not persist when the database is restarted. To make the setting persistent without using a spfile, you will need to manually specify the parameter in the initialization parameter file (init.ora).

To disable workload capture, run the wrrdsbl.sql script at the SQL prompt:

@$ORACLE_HOME/rdbms/admin/wrrdsbl.sql

The wrrdsbl.sql script calls the ALTER SYSTEM SQL statement to set the PRE_11G_ENABLE_CAPTURE initialization parameter to FALSE. If a server parameter file (spfile) is being used, the PRE_11G_ENABLE_CAPTURE initialization parameter will be modified for the currently running instance and also recorded in the spfile, so that the new setting will persist when the database is restarted. If a spfile is not being used, the PRE_11G_ENABLE_CAPTURE initialization parameter will only be modified for the currently running instance, and the new setting will not persist when the database is restarted. To make the setting persistent without using a spfile, you will need to manually specify the parameter in the initialization parameter file (init.ora).

Note:

The PRE_11G_ENABLE_CAPTURE initialization parameter can only be used with Oracle Database 10g Release 2 (10.2). This parameter is not valid in subsequent releases. After upgrading the database, you will need to remove the parameter from the server parameter file (spfile) or the initialization parameter file (init.ora); otherwise, the database will fail to start up.

See Also:

- Oracle Database Reference for more information about the PRE_11G_ENABLE_CAPTURE initialization parameter

Enterprise Manager Privileges and Roles

The Database Replay resource type privileges enable you to view or operate any Database Replay entities. Additionally, you need the target operator privilege for the target from which the workload was captured to access the entities associated with the workload. For a target that does not exist anymore, the Enterprise Manager user who owns the entities or the Enterprise Manager super user can still access the entities.

The two security roles discussed in the following sections make it easier to grant or revoke privileges related to Database Replay entities.

Database Replay Viewer Role

Users who have the Database Replay Viewer role can view any Database Replay entity. By default, no Enterprise Manager user is granted this role. However, the EM_ALL_VIEWER role includes this role by default.

The Database Replay Viewer role consists of the following privilege:

- Database Replay Viewer (resource type privilege)

Database Replay Operator Role

The Database Replay Operator role includes the Database Replay Viewer role and thus its privileges. Users who have the Database Replay Operator role can also edit and delete any Database Replay entity. By default, no Enterprise Manager user is granted this role. However, the EM_ALL_OPERATOR role includes this role by default.

The Database Replay Operator role consists of the following privileges:

- Database Replay Operator (resource type privilege)

- Create new Named Credential (resource type privilege)

- Create new job (resource type privilege)

- Connect to any viewable target (target type privilege)

- Execute Command Anywhere (target type privilege)

To capture or replay a workload on a database target, an Enterprise Manager user needs all the privileges granted by the Database Replay Operator role plus the target operator privilege for the database target.

Capturing a Database Workload Using Enterprise Manager

This section describes how to capture a database workload using Enterprise Manager. The primary tool for capturing database workloads is Oracle Enterprise Manager.

Tip:

If Oracle Enterprise Manager is unavailable, you can capture database workloads using APIs, as described in "Capturing a Database Workload Using APIs".

To capture a database workload using Enterprise Manager:

1. From the Enterprise menu of the Enterprise Manager Cloud Control console, select Quality Management, then Database Replay.

If the Database Login page appears, log in as a user with administrator privileges.

The Database Replay page appears.

2. From the Database Replay page, click the Captured Workloads tab, then click Create in the toolbar.

The Create Capture: Plan Environment page appears.

3. Verify that you have met both prerequisites described on this page, then enable both checkboxes and click Next.

The Create Capture: Database page appears.

Tip:

For information about the prerequisites, see "Prerequisites for Capturing a Database Workload".

4. Click Add.

The Add pop-up appears.

5. Provide a capture name, provide an optional description, then click the Target Database search icon.

The Search and Select: Targets pop-up appears.

6. Select a Target Type, optionally provide a configuration search, choose a target database from the list, then click Select.

The Add pop-up reappears with added sections for Database Credential and Database Host Credential.

7. Provide database credentials, database host credentials, a Database Capture Intermediate Storage Location, then click OK.

- After the Capture, the files are copied to the storage location, unless you use the intermediate storage location as the final storage location.

Note:

For captures on an Oracle RAC database, Enterprise Manager only supports Oracle RAC configured with a shared file system.

The selected target database now appears in the list of databases in the Select Production Databases table.

8. Click Next.

The Create Capture: Options page appears.

9. Select the workload capture options:

- Under the SQL Performance Analyzer section, select whether to capture SQL statements into a SQL tuning set during workload capture.

While Database Replay provides an analysis of how a change affects your entire system, you can use a SQL tuning set in conjunction with the SQL Performance Analyzer to gain a more SQL-centric analysis of how the change affects SQL statements and execution plans.

By capturing a SQL tuning set during workload capture and another SQL tuning set during workload replay, you can use the SQL Performance Analyzer to compare these SQL tuning sets to each other without having to re-execute the SQL statements. This enables you to obtain a SQL Performance Analyzer report and compare the SQL performance, before and after changes, while running Database Replay.

Note:

Capturing SQL statements into a SQL Tuning Set is the default, and is the recommended workload capture option. Capturing SQL statements into a SQL Tuning Set is not available for Oracle RAC.

Tip:

For information about comparing SQL tuning sets using SQL Performance Analyzer reports, see "Generating SQL Performance Analyzer Reports Using APIs".

- Under the Workload Filters section, select whether to use exclusion filters by selecting Exclusion in the Filter Mode list, or inclusion filters by selecting Inclusion in the Filter Mode list.
To add filters, click Add and enter the filter name, session attribute, and value in the corresponding fields.

Tip:

For more information, see "Using Filters with Workload Capture".

After selecting the desired workload capture options, click Next.

The Create Capture: Storage page appears.

10. Click the Storage Host icon, choose a target from the list, then click Select.

The Storage page now requests Host Credentials and a Storage Location.

11. Provide Host Credentials, click Browse to select a Storage Location, select the location and click OK, then click Next.

The Create Capture: Schedule page appears.

12. Schedule the starting time and duration for the capture, schedule the exporting of AWR data, then click Next.

- The default capture duration is 5 minutes. Change the capture duration to capture representative activity over a time period of interest that needs to be tested.

The Create Capture: Review page appears.

13. If all of the parameters appear as you have intended, click Submit to start the capture job.

- The "Capture SQL statements into a SQL Tuning Set during workload capture" option is enabled by default. Uncheck this option if you do not want to compare SQL tuning sets at the end of the Replay.

The Database Replay page reappears, displays a message that the capture was created successfully, and displays the status of the capture in the Captures list, such as "Scheduled."

14. For detailed information about the capture, double-click the name of the capture.

The Capture Summary page appears, and displays several attributes, including the average active sessions, a workload comparison, and related concurrent captures, if any.

Tip:

After capturing a workload on the production system, you need to preprocess the captured workload, as described in Preprocessing a Database Workload .

Capturing Workloads from Multiple Databases Concurrently

Concurrent capture refers to capturing the workload on multiple databases simultaneously.

To capture a concurrent database replay workload:

1. From the Enterprise menu of the Enterprise Manager Cloud Control console, select Quality Management, then Database Replay.
If the Database Login page appears, log in as a user with administrator privileges.

The Database Replay page appears.

2. From the Database Replay page, click the Captured Workloads tab, then click Create in the toolbar.
The Create Capture: Plan Environment page appears.

3. Make sure that you have met both prerequisites described on this page, then enable both checkboxes and click Next.
The Create Capture: Database page appears.

Tip:

For information about the prerequisites, see "Prerequisites for Capturing a Database Workload".

4. Click Add.

The Add pop-up appears.

5. Provide a Capture name, provide an optional description, then click the Target Database search icon.
The Search and Select: Targets pop-up appears.

6. Choose a target database from the list, then click Select.
The Add pop-up reappears with added sections for Database Credential and Database Host Credential.

7. Provide database credentials, database host credentials, a Database Capture Intermediate Storage Location, then click OK.

- After the Capture, the files are copied to the storage location, unless you use the intermediate storage location as the final storage location.

The selected target database now appears in the list of databases in the Select Production Databases table.

8. Add another database for concurrent capture:

a. Follow the instructions in steps 4 through 7.
The Create Capture: Database page reappears, and displays the additional database for capture along with the first database you specified in steps 4 through 7.

b. Provide a name and optional description for the concurrent capture, then click Next.
The Create Capture: Options page appears.

9. Select the workload capture options:

- Under the SQL Performance Analyzer section, select whether to capture SQL statements into a SQL tuning set during workload capture.
While Database Replay provides an analysis of how a change affects your entire system, you can use a SQL tuning set in conjunction with the SQL Performance Analyzer to gain a more SQL-centric analysis of how the change affects SQL statements and execution plans.

By capturing a SQL tuning set during workload capture and another SQL tuning set during workload replay, you can use the SQL Performance Analyzer to compare these SQL tuning sets to each other without having to re-execute the SQL statements. This enables you to obtain a SQL Performance Analyzer report and compare the SQL performance, before and after changes, while running Database Replay.

Note:

Capturing SQL statements into a SQL tuning set is the default and recommended workload capture option.

- Under the Workload Filters section, select whether to use exclusion filters by selecting Exclusion in the Filter Mode list, or inclusion filters by selecting Inclusion in the Filter Mode list.
To add filters, click Add and enter the filter name, session attribute, and value in the corresponding fields.

After selecting the desired workload capture options, click Next.

The Create Capture: Storage page appears.

10. Click the Storage Host icon, choose a target from the list, then click Select.
The Storage page now requests Host Credentials and a Storage Location.

11. Provide Host Credentials, click Browse to select a Storage Location, then click Next.
The Create Capture: Schedule page appears.

12. Schedule the starting time and duration for the capture, schedule the exporting of AWR data, then click Next.

- The default capture duration is 5 minutes. Change the capture duration to capture representative activity over a time period of interest that needs to be tested.

The Create Capture: Review page appears.

13. If all of the parameters appear as you have intended, click Submit to start the Capture job.

- The "Capture SQL statements into a SQL Tuning Set during workload capture" option is enabled by default. Uncheck this option if you do not want to compare SQL tuning sets at the end of the Replay.

The Database Replay page reappears, displays a message that the capture was created successfully, and displays the status of the capture in the Captures list, such as "Scheduled."

14. For detailed information about the capture, double-click the name of the capture.
The Capture Summary page appears, and displays several attributes, including the average active sessions, a workload comparison, and related concurrent captures.

Monitoring a Workload Capture Using Enterprise Manager

This section describes how to monitor workload capture using Enterprise Manager. The primary tool for monitoring workload capture is Oracle Enterprise Manager. Using Enterprise Manager, you can:

- Monitor or stop an active workload capture

- View a completed workload capture

Tip:

If Oracle Enterprise Manager is unavailable, you can monitor workload capture using views, as described in "Monitoring Workload Capture Using Views".

This section contains the following topics:

- Monitoring an Active Workload Capture

- Stopping an Active Workload Capture

- Viewing a Completed Workload Capture

Monitoring an Active Workload Capture

This section describes how to monitor an active workload capture using Enterprise Manager.

To monitor an active workload capture:

1. From the Enterprise menu of the Enterprise Manager Cloud Control console, select Quality Management, then Database Replay.

If the Database Login page appears, log in as a user with administrator privileges.

The Database Replay page appears.

2. From the Captured Workloads tab of the Database Replay page for a capture that has a Status other than Completed, click the name of the desired capture from the Capture table.

The Summary tab of the Database Replay page appears, showing detailed statistics, a chart for average active sessions that updates dynamically while the capture is in progress, a comparison of data for captured elements versus the same elements not captured, and related concurrent captures, if any.

- The Not Captured data shown in the Active Average Sessions chart shows the database activity (database sessions) that is not being captured.

- The values for the Total column in the Comparison section shows all of the captured and uncaptured activity in the database. Filtering, as determined by the Workload Filters you provided in the Options step of the Create Capture wizard, is primarily why some activity is captured or not. Additionally, background activities, database scheduler jobs, and unreplayable calls are not captured.

- You can click the refresh icon in the upper right corner to update the capture while it is running.

3. To return to the Database Replay page, click the Database Replay breadcrumb.

Stopping an Active Workload Capture

This section describes how to stop an active workload capture using Enterprise Manager.

To stop an active workload capture:

1. From the Enterprise menu of the Enterprise Manager Cloud Control console, select Quality Management, then Database Replay.

If the Database Login page appears, log in as a user with administrator privileges.

The Database Replay page appears.

2. From the Captured Workloads tab of the Database Replay page for a capture that has a Status of Draft, click the name in the Capture table of the capture you want to stop.

The Capture Summary page appears.

3. Click the Stop Capture button.

The button label changes to Stopping Capture. When the process completes, the Status changes to Stopped.

Viewing a Completed Workload Capture

This section describes how to manage a completed workload capture using Enterprise Manager.

To view a completed workload capture:

1. From the Enterprise menu of the Enterprise Manager Cloud Control console, select Quality Management, then Database Replay.

If the Database Login page appears, log in as a user with administrator privileges.

The Database Replay page appears.

2. From the Capture Workloads tab of the Database Replay page, click the name of a capture that has a Status of Completed.

The contents of the Summary tab of the Database Replay page appears as for a capture in progress, except the Average Active Sessions chart shows aggregated data for the capture time period, rather than dynamic data recorded during the capture.

The Average Active Sessions chart provides a graphic display of the captured session activity compared to the uncaptured session activity (such as background activities or filtered sessions). This chart appears only when Active Session History (ASH) data is available for the capture period.

Under Comparison, various statistics for the workload capture are displayed:

- Capture column
Displays the statistics for the captured session activity.

- Total column
Displays the statistics for the total session activity.

- Percentage of Total column
Displays the percentage of total session activity that has been captured in the workload.

3. To return to the Database Replay page, click the Database Replay breadcrumb.

Tip:

See Analyzing Captured and Replayed Workloads for information about accessing workload capture reports.

Importing a Workload External to Enterprise Manager

You can import a workload captured through the PL/SQL interface or through a different Enterprise Manager instance into Enterprise Manager to manage it as you would for a workload originally created within Enterprise Manager. The workload can be in the process of being captured, or the Capture can be completed and the workload stored on a file system. You can also preprocess and replay the workload as you would ordinarily do for a workload created within Enterprise Manager.

This feature is available for Cloud Control Database plug-in 12.1.0.5 and later releases.

To import a database workload external to Enterprise Manager:

1. From the Database Replay page, click the Captured Workloads tab, then click Import in the toolbar.
The Import Workload: Source page appears.

2. Select one of the three choices available to import a captured workload, then click Next:

- Import a completed captured workload from a directory in the file system
This option typically applies for a workload created using an API, in which you now want to import it to Enterprise Manager for subsequent processing. In this case, Enterprise Manager may not even be managing the Capture database.

- Import a completed captured workload from a database target
In this case, Enterprise Manager is probably already managing the Capture database. The Capture could have been done on this database, or it could have been loaded in as would be the case for the option above.

- Attach to a Capture running in a database target
This option is similar to the option above, except this a Capture that is still in progress, rather than one that has already completed.

The Import Workload: Database page appears.

3. Click the search icon next to the Database Target field and select a database from the pop-up that appears.

Note:

The target version of the database loading the workload must be at least as high as the one you used to capture the workload. For instance, if you captured using Oracle Database 12x, the database you select to read the Capture must be at least version 12x.

- The system now requests database and host credentials.

- In the previous step, if you chose to import a completed captured workload from a directory in the file system, the system also requires a workload location.

- A consolidated Replay has a different directory structure in which there are at least two capture directories. Consequently, if the workload directory contains a consolidated Replay, you need to enable the check box so that Enterprise Manager can be aware of the consolidated Replay during the import operation.

4. Provide the requisite input for the step above, then click Next.
The Import Workload: Workload page appears.

- If you chose "Import a completed captured workload from a directory in the file system" in step 2, this page provides a Load Workload button.

- If you chose “Import a completed captured workload from a database target" or “Attach to a Capture running in a database target" in step 2, this page provides a Discover Workload button.

5. Click either Load Workload or Discover Workload, depending on which button is available in accordance with your selection in step 2.
The system displays workloads, if found, in the Discovered Workloads table.

6. Either click Next to load the workload, or select one of the workloads, then click Next to continue importing the workload.
The Import Workload: Replay page appears only under the following conditions:

- You chose "Import a completed captured workload from a directory in the file system" in step 2.

- The workload contains one or more Replays.

7. Optional: Select one or more Replays, if desired, provide a Replay Task Name, then click Next.
The Import Workload: Review page appears.

8. If everything appears as you have intended, click Submit.
The Database Replay page reappears and displays a message stating that the job was submitted successfully. The Status column for your loaded or imported workload in the Captured Workload table will show In Progress.

Tip:

You can check on the job's progress by clicking on the captured workload name that you just submitted in the Review step. A Capture Summary page appears, and you can click the Database Replay Import Job link to see the progress of the job execution steps.

Creating Subsets from an Existing Workload

For cases in which you have captured a large workload covering a long period of time, you may only want to replay a portion of it to accelerate testing. The Database Replay Workload Subsetting feature enables you to create new workloads by extracting portions of an existing captured workload.

Enterprise Manager provides a wizard to extract a subset of data from an existing workload that you can use for Replay on a test system. Each extracted subset is a legitimate workload that can be replayed on its own or with other workloads in a consolidated Replay.

To perform a Replay, you need to preprocess the workloads.

This feature is available for Cloud Control Database plug-in 12.1.0.5 and later releases.

To extract subsets from a workload:

1. From the Captured Workloads tab of the Database Replay page, select a workload for which you want to extract a subset, then click Subset.
The Subset Workload: Define page appears, showing an Active Sessions History chart for the workload.

2. Select a starting and ending time for the subset you want to extract from the workload:

a. Click Add above the Subsets table at the bottom of the page.
The Create Subset pop-up appears.

b. Select either snapshot or calendar times, provide start and end times, then click OK.

Note:

Snapshot time is the preferred choice, because not all performance data may be available for the calendar time you select.

Your selected time period now appears in the Active Sessions chart as a greyed-out segment.

c. Optional: Define one or more additional subsets with different time periods than those you selected in the step above.

d. Optional: In the Advanced Parameters section, indicate whether you want to include incomplete calls after the subset workload ends. The default is to include incomplete calls when the subset workload begins.

- These parameters enable you to include the calls outside of your defined boundaries. For example, when you specify a starting and ending time as the boundaries for a transaction, the transaction may have started before your indicated start time, and may also have continued after your indicated end time.

3. Click Next.
The Subset Workload: Database page appears.

4. Click the search icon next to the Database Target field and select a database for subsetting from the Search and Select: Targets pop-up that appears.
The system now requests database and host credentials.

5. Provide the requisite input for the step above, then click Next.
The Subset Workload: Location page appears.

- If the source host and staged database host are the same, the location is pre-populated, so you do not need to provide the location for the source workload files.

- If the source host and staged database host are not the same, do the following:

a. Choose whether you want to access the workload files from the host name shown in the Host field, or whether you want to copy the files from the source host to the Destination Host shown.
Access Directly means that the database to be used to subset the workload can access the original workload directly using the specified file system location. This is typically the case when the original workload is stored at a network shared location.

Access Copy means that the two hosts are not in the shared network path. You need to provide the source host credentials so that Enterprise Manager can copy the original workload from its current location to the specified location on the subset database host.

b. Depending on your choice above, either provide the directory location containing the workload files, or provide the location for the destination host.

6. In the Subset field, specify the storage location for each subset, then click Next.
The Subset Workload: Schedule page appears.

7. Indicate when you want to start the subset job, then click Next.
The Subset Workload: Review page appears.

8. If everything appears as you have intended, click Submit.
The Database Replay page reappears and displays a message stating that the job was submitted successfully. The Status column for your subset in the Replay Tasks table will show In Progress.

Tip:

You can check on the job's progress by clicking on the subset name that you just submitted in the Review step. A Capture Summary page appears, and you can click the Database Replay Subset Job link to see the progress of the job execution steps.

Copying or Moving a Workload to a New Location

You can use the copy function for two purposes:

- Duplicate the Capture files from the source to another host and location.

- Move the Capture files to a new host and location, and delete the source files from the original location.

This feature is available for Cloud Control Database plug-in 12.1.0.5 and later releases.

To copy a workload to a new location:

1. From the Captured Workloads tab of the Database Replay page, select a workload you want to copy to a new location, then click Copy.
The Copy Workload page appears, and displays the current source location of the workload directory you selected.

2. Provide or change credentials for the storage host, if necessary. The system automatically picks up the previously defined credentials for the current storage host.

3. Leave the After Copy radio button enabled, which is "Keep original workload in the source location."

4. Select the Storage Host for the new location of the workload directory.

5. Provide credentials for the new storage host.

6. Select the directory for the new Destination Location for the workload.

7. Schedule the job, then click Submit.
The Database Replay page reappears and displays a message stating that the job was submitted and that the storage location has been updated successfully.

Tip:

You can check on the job's progress by going to the Job Activity page, searching for the job name that appeared in the submit message, then clicking its link to access the Job Run page.

Capturing a Database Workload Using APIs

This section describes how to capture a database workload using APIs. You can also use Oracle Enterprise Manager to capture database workloads, as described in "Capturing a Database Workload Using Enterprise Manager".

Capturing a database workload using the DBMS_WORKLOAD_CAPTURE package involves:

- Defining Workload Capture Filters

- Starting a Workload Capture

- Stopping a Workload Capture

- Exporting AWR Data for Workload Capture

- Importing AWR Data for Workload Capture

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_WORKLOAD_CAPTURE package

Defining Workload Capture Filters

This section describes how to add and remove workload capture filters. For information about using workload filters with workload capture, see "Using Filters with Workload Capture".

To add filters to a workload capture:

- Use the ADD_FILTER procedure:

BEGIN
DBMS_WORKLOAD_CAPTURE.ADD_FILTER (
fname => 'user_ichan',
fattribute => 'USER',
fvalue => 'ICHAN');
END;
/

In this example, the ADD_FILTER procedure adds a filter named user_ichan, which can be used to filter out all sessions belonging to the user name ICHAN.

The ADD_FILTER procedure in this example uses the following parameters:

- The fname required parameter specifies the name of the filter that will be added.

- The fattribute required parameter specifies the attribute on which the filter will be applied. Valid values include PROGRAM, MODULE, ACTION, SERVICE, INSTANCE_NUMBER, and USER.

- The fvalue required parameter specifies the value for the corresponding attribute on which the filter will be applied. It is possible to use wildcards such as % with some of the attributes, such as modules and actions.

To remove filters from a workload capture:

- Use the DELETE_FILTER procedure:

BEGIN
DBMS_WORKLOAD_CAPTURE.DELETE_FILTER (fname => 'user_ichan');
END;
/

In this example, the DELETE_FILTER procedure removes the filter named user_ichan from the workload capture.

The DELETE_FILTER procedure in this example uses the fname required parameter, which specifies the name of the filter to be removed. The DELETE_FILTER procedure will not remove filters that belong to completed captures; it only applies to filters of captures that have yet to start.

Starting a Workload Capture

Before starting a workload capture, you must first complete the prerequisites for capturing a database workload, as described in "Prerequisites for Capturing a Database Workload". You should also review the workload capture options, as described in "Workload Capture Options".

It is important to have a well-defined starting point for the workload so that the replay system can be restored to that point before initiating a replay of the captured workload. To have a well-defined starting point for the workload capture, it is preferable not to have any active user sessions when starting a workload capture. If active sessions perform ongoing transactions, those transactions will not be replayed properly in subsequent database replays, since only that part of the transaction whose calls were executed after the workload capture is started will be replayed. To avoid this problem, consider restarting the database in restricted mode using STARTUP RESTRICT before starting the workload capture. Once the workload capture begins, the database will automatically switch to unrestricted mode and normal operations can continue while the workload is being captured. For more information about restarting the database before capturing a workload, see "Restarting the Database".

To start a workload capture:

- Use the START_CAPTURE procedure:

BEGIN
DBMS_WORKLOAD_CAPTURE.START_CAPTURE (name => 'dec10_peak',
dir => 'dec10',
duration => 600,
capture_sts => TRUE,
sts_cap_interval => 300);
END;
/

In this example, a workload named dec10_peak will be captured for 600 seconds and stored in the file system defined by the database directory object named dec10. A SQL tuning set will also be captured in parallel with the workload capture.

The START_CAPTURE procedure in this example uses the following parameters:

- The name required parameter specifies the name of the workload that will be captured.

- The dir required parameter specifies a directory object pointing to the directory where the captured workload will be stored.

- The duration parameter specifies the number of seconds before the workload capture will end. If a value is not specified, the workload capture will continue until the FINISH_CAPTURE procedure is called.

- The capture_sts parameter specifies whether to capture a SQL tuning set in parallel with the workload capture. If this parameter is set to TRUE, you can capture a SQL tuning set during workload capture, then capture another SQL tuning set during workload replay, and use SQL Performance Analyzer to compare the SQL tuning sets without having to re-execute the SQL statements. This enables you to obtain a SQL Performance Analyzer report and compare the SQL performance—before and after the change—while running Database Replay. You can also export the resulting SQL tuning set with its AWR data using the EXPORT_AWR procedure, as described in "Exporting AWR Data for Workload Capture".
This feature is not supported for Oracle RAC. Workload capture filters that are defined using DBMS_WORKLOAD_CAPTURE do not apply to the SQL tuning set capture. The default value for this parameter is FALSE.

- The sts_cap_interval parameter specifies the duration of the SQL tuning set capture from the cursor cache in seconds. The default value is 300. Setting the value of this parameter below the default value may cause additional overhead with some workloads and is not recommended.

Stopping a Workload Capture

This section describes how to stop a workload capture.

To stop a workload capture:

- Use the FINISH_CAPTURE procedure:

BEGIN
DBMS_WORKLOAD_CAPTURE.FINISH_CAPTURE ();
END;
/

In this example, the FINISH_CAPTURE procedure finalizes the workload capture and returns the database to a normal state.

Tip:

After capturing a workload on the production system, you need to preprocess the captured workload, as described in Preprocessing a Database Workload .

Exporting AWR Data for Workload Capture

Exporting AWR data enables detailed analysis of the workload. This data is also required if you plan to run the Replay Compare Period report or the AWR Compare Period report on a pair of workload captures or replays.

To export AWR data:

- Use the EXPORT_AWR procedure:

BEGIN
DBMS_WORKLOAD_CAPTURE.EXPORT_AWR (capture_id => 2);
END;
/

In this example, the AWR snapshots that correspond to the workload capture with a capture ID of 2 are exported, along with any SQL tuning set that may have been captured during workload capture.

The EXPORT_AWR procedure uses the capture_id required parameter, which specifies the ID of the capture whose AWR snapshots will be exported. The value of the capture_id parameter is displayed in the ID column of the DBA_WORKLOAD_CAPTURES view.

Note:

This procedure works only if the corresponding workload capture was performed in the current database and the AWR snapshots that correspond to the original capture time period are still available.

See Also:

Oracle Database Reference for information about the DBA_WORKLOAD_CAPTURES view

Importing AWR Data for Workload Capture

After AWR data is exported from the capture system, you can import the AWR data into another system, such as a test system where the captured workload will be replayed. Importing AWR data enables detailed analysis of the workload. This data is also required if you plan to run the Replay Compare Period report or the AWR Compare Period report on a pair of workload captures or replays.

To import AWR data:

- Use the IMPORT_AWR function, as shown in the following example:

CREATE USER capture_awr
SELECT DBMS_WORKLOAD_CAPTURE.IMPORT_AWR (capture_id => 2,
staging_schema => 'capture_awr')
FROM DUAL;

In this example, the AWR snapshots that correspond to the workload capture with a capture ID of 2 are imported using a staging schema named capture_awr.

The IMPORT_AWR procedure in this example uses the following parameters:

- The capture_id required parameter specifies the ID of the capture whose AWR snapshots will be import. The value of the capture_id parameter is displayed in the ID column of the DBA_WORKLOAD_CAPTURES view.

- The staging_schema required parameter specifies the name of a valid schema in the current database which can be used as a staging area while importing the AWR snapshots from the capture directory to the SYS AWR schema.

Note:

This function fails if the schema specified by the staging_schema parameter contains any tables with the same name as any of the AWR tables.

See Also:

Oracle Database Reference for information about the DBA_WORKLOAD_CAPTURES view

Monitoring Workload Capture Using Views

This section summarizes the views that you can display to monitor workload capture. You can also use Oracle Enterprise Manager to monitor workload capture, as described in "Monitoring a Workload Capture Using Enterprise Manager".

To access these views, you need DBA privileges:

- The DBA_WORKLOAD_CAPTURES view lists all the workload captures that have been captured in the current database.

- The DBA_WORKLOAD_FILTERS view lists all workload filters used for workload captures defined in the current database.

See Also:

- Oracle Database Reference for information about the DBA_WORKLOAD_CAPTURES view

- Oracle Database Reference for information about the DBA_WORKLOAD_FILTERS view

11 Preprocessing a Database Workload

After a workload is captured and setup of the test system is complete, the captured data must be preprocessed. Preprocessing a captured workload creates all necessary metadata for replaying the workload. This must be done once for every captured workload before they can be replayed. After the captured workload is preprocessed, it can be replayed repeatedly on a replay system.

To preprocess a captured workload, you will first need to move all captured data files from the directory where they are stored on the capture system to a directory on the instance where the preprocessing will be performed. Preprocessing is resource intensive and should be performed on a system that is:

- Separate from the production system

- Running the same version of Oracle Database as the replay system

For Oracle Real Application Clusters (Oracle RAC), select one database instance of the replay system for the preprocessing. This instance must have access to the captured data files that require preprocessing, which can be stored on a local or shared file system. If the capture directory path on the capture system resolves to separate physical directories in each instance, you will need to merge them into a single capture directory where the preprocessing will be performed. All directories must have the same directory tree and all files contained in each of these directories must be moved into a directory that has the same relative path to the capture directory.

Typically, you will preprocess the captured workload on the replay system. If you plan to preprocess the captured workload on a system that is separate from the replay system, you will also need to move all preprocessed data files from the directory where they are stored on the preprocessing system to a directory on the replay system after preprocessing is complete.

This chapter contains the following sections:

- Preparing a Single Database Workload Using Enterprise Manager

- Preprocessing a Database Workload Using APIs

Tip:

Before you can preprocess a captured workload, you must first capture the workload on the production system, as described in Capturing a Database Workload .

Preparing a Single Database Workload Using Enterprise Manager

Preparing for a single workload consists of the following tasks:

- Creating a database replay task

- Creating a replay from a replay task

- Preparing the test database

- Preprocessing the workload and deploying the replay clients

Note:

Preparing the test database is only required if you have not done so already.

The following sections provide procedures for these tasks.

Creating a Database Replay Task

Before creating a database replay task, make sure that the capture that you want to replay has some captured user calls.

To create a database replay task:

1. From the Database Replay page, click the Replay Tasks tab, then click Create in the toolbar.
The Create Task page appears.

2. Provide a Name for the task, select a capture to be replayed, then click Submit. For consolidated replays, select two or more captures.
The Database Replay page reappears, and displays your newly created replay task in the table under the Replay Task tab.

Creating a Replay from a Replay Task

To create the replay:

1. From the Database Replay page, click the Replay Tasks tab.

2. Click the link for the desired replay task in the table.
The Replay Task page for the capture appears.

3. Click Create in the Replays section.
The Create Replay pop-up appears.

4. Provide a required Name and optional description, then click the Target Database icon.
The Search and Select: Targets pop-up appears.

5. Choose the desired database, then click Select.

6. Click OK in the Create Replay pop-up.
The Database Replay page for your replay appears, which includes a Task List with links to perform the needed tasks.

You can now proceed to the first task in the Task List, described in the next section.

Preparing the Test Database

Preparing the test database consists of:

- Setting up the test database

- Isolating the test database

Note:

These tasks are optional. If you have already set up your test database, skip to "Preprocessing the Workload and Deploying the Replay Clients".

The following procedures explain how to perform each of these tasks, which you can do in any order.

To set up the test database:

1. From the Replay page for your particular replay, click the link for the Set Up Test Database task.
The Set Up Test Database page appears.

2. Choose whether you want to upgrade the database or not, and indicate whether this is a cluster database.

3. Click the Go to Task icon for the Clone Existing Database Software sub-task, or click Enable All Tasks if you want to create the test database first.

4. Follow the instructions provided in the online help for the wizards.
When the tasks are complete, a checkmark appears in the Status column for each task.

5. Click OK to return to the Database Replay page.

To isolate the test database:

1. From the Replay page for your particular replay, click the link for the Isolate Test Database task.
A page appears explaining that references to external systems can cause problems during the replay.

2. Use the links provided to verify potential references to external systems, modify those that are invalid, then click OK.
The Replay Summary page reappears.

Preprocessing the Workload and Deploying the Replay Clients

The final preparation for the replay consists of:

- Preprocessing the workload
You need to preprocess each captured workload once for each version of the database against which the workload will be replayed. After you preprocess the workload once, you can use it for any subsequent replay tasks and replays without needing to preprocess again, as long as the test database is the same version as the database where the workload was preprocessed.For instance, for a replay task that contains two replays named "MyReplay1" and "MyReplay2," after you have preprocessed "MyReplay1", you can just directly reuse the directory object to replay "MyReplay2."

The Workload Analyzer report is available after preprocessing.

- Deploying the replay clients
You do not need to deploy the replay clients to other replay client hosts if these hosts can access the Oracle home of the test database you specified in the Database Target Name field.

The following procedures explain how to accomplish each of these tasks.

To preprocess the workload:

1. From the Replay page for your particular replay, click the link for the Preprocess Workload task.
The Preprocess Captured Workload: Locate Workload page appears.

2. Select the desired workload location option, then click Next.

Note:

You initially need to select the copy option.

The Preprocess Captured Workload: Copy Workload page appears.

3. Provide the required credentials and the new location to which the workloads will be copied and preprocessed, then click Next.

- For a consolidated replay, there are multiple source workloads, so multiple source credentials might be needed for the current location of the workload directory. For more information on consolidated replays, see "Using Consolidated Database Replay with Enterprise Manager."

The system responds by displaying a progress bar graph during processing, then displays the Preprocess Captured Workload: Select Directory page after the copy operation concludes.

4. Specify the Directory Object, or create a new Directory Object that points to the location that contains the workload. If you chose to copy from the workload location to a new location in the previous step, make sure that the directory object points to the exact location you specified in the New Location of the Workload Directory section.
The system responds by displaying a Capture Summary. You can now expand the Capture Details section to see the workload profile and workload filters. The Capture Summary does not appear for consolidated replays.

Click Next to display the Preprocess Captured Workload: Schedule page.

5. Provide input to schedule the preprocess job:

a. Provide your own required job name or accept the system-supplied name. The job system automatically names the job in uppercase.

b. Indicate whether you want the job to run as soon as you submit it, or whether you want it to run at a later time.

c. Provide the host credentials, which are used to run the preprocess job in the operating system.

Click Next to display the Preprocess Captured Workload: Review page.

6. Check to make sure that the settings are what you intend, then click Submit.
The Database Replay page appears, and assuming that there were no errors in your input, a confirmation message at the top of the page states "Job JOBNAME to prepare the workload has been created successfully."

7. Click the JOBNAME link to check the status of the job. The job must succeed before you can proceed to the Replay Workload task.

Note:

A message may appear in the Task List stating that you need to install an additional PL/SQL package in the test database to generate a compare period report after the trial. Click Install PL/SQL Package to resolve this issue before proceeding to the Replay Workload task.

Tip:

After preprocessing a captured workload, you can replay it on the test system, as described in Replaying a Database Workload .

To deploy the replay clients:

1. From the Replay page for your particular replay, click the link for the Deploy Replay Clients task.
The Deploy Replay Clients page appears.

2. Accept the default values defined for the associated workload capture, or override these values, then click Continue.
The Provision Oracle Database Client wizard appears.

3. Follow the instructions provided in the online help for each step of the wizard.
After you click Submit in the Review step to run the deployment procedure according to the schedule you have set, the Replay Summary page reappears.

Preprocessing a Database Workload Using APIs

This section describes how to preprocess a captured workload using the DBMS_WORKLOAD_REPLAY package. You can also use Oracle Enterprise Manager to preprocess a captured workload, as described in "Preparing a Single Database Workload Using Enterprise Manager".

To preprocess a captured workload:

- Use the PROCESS_CAPTURE procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.PROCESS_CAPTURE (capture_dir => 'dec06');
END;
/

In this example, the captured workload stored in the dec06 directory will be preprocessed.

The PROCESS_CAPTURE procedure in this example uses the capture_dir required parameter, which specifies the directory that contains the captured workload to be preprocessed.

Tip:

After preprocessing a captured workload, you can replay it on the test system, as described in Replaying a Database Workload .

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_WORKLOAD_REPLAY package

Running the Workload Analyzer Command-Line Interface

The Workload Analyzer is a Java program that analyzes a workload capture directory and identifies parts of a captured workload that may not replay accurately due to insufficient data, errors that occurred during workload capture, or usage features that are not supported by Database Replay. The results of the workload analysis are saved to an HTML report named wcr_cap_analysis.html located in the capture directory that is being analyzed. If an error can be prevented, the workload analysis report displays available preventive actions that can be implemented before replay. If an error cannot be corrected, the workload analysis report provides a description of the error so it can be accounted for during replay. Running Workload Analyzer is the default option and is strongly recommended.

Note:

If you are preprocessing a workload capture using Oracle Enterprise Manager, then you do not need to run Workload Analyzer in the command-line interface. Oracle Enterprise Manager enables you to run Workload Analyzer as part of the workload preprocessing.

Workload Analyzer is composed of two JAR files, dbranalyzer.jar and dbrparser.jar, located in the $ORACLE_HOME/rdbms/jlib/ directory of a system running Oracle Database Enterprise Edition Release 11.2.0.2 or higher. Workload Analyzer requires Java 1.5 or higher and the ojdbc6.jar file located in the $ORACLE_HOME/jdbc/lib/ directory.

To run Workload Analyzer:

1. In the command-line interface, run the following java command on a single line:

java -classpath
$ORACLE_HOME/jdbc/lib/ojdbc6.jar:$ORACLE_HOME/rdbms/jlib/dbrparser.jar:
$ORACLE_HOME/rdbms/jlib/dbranalyzer.jar:
oracle.dbreplay.workload.checker.CaptureChecker
<capture_directory> <connection_string>

For the capture_directory parameter, input the operating system path of the capture directory. This directory should also contain the exported AWR data for the workload capture. For the connection_string parameter, input the connection string of an Oracle database that is release 11.1 or higher.

An example of this command may be:

java -classpath
$ORACLE_HOME/jdbc/lib/ojdbc6.jar:$ORACLE_HOME/rdbms/jlib/dbrparser.jar:
$ORACLE_HOME/rdbms/jlib/dbranalyzer.jar:
oracle.dbreplay.workload.checker.CaptureChecker /scratch/capture
jdbc:oracle:thin:@myhost.mycompany.com:1521:orcl

2. When prompted, input the username and password of a database user with EXECUTE privileges for the DBMS_WORKLOAD_CAPTURE package and the SELECT_CATALOG role on the target database.

12 Replaying a Database Workload

After a captured workload is preprocessed, it can be replayed repeatedly on a replay system that is running the same version of Oracle Database. Typically, the replay system where the preprocessed workload will be replayed should be a test system that is separate from the production system.

This chapter describes how to replay a database workload on the test system and contains the following sections:

- Steps for Replaying a Database Workload

- Replaying a Database Workload Using Enterprise Manager

- Setting Up the Replay Schedule and Parameters Using Enterprise Manager

- Monitoring Workload Replay Using Enterprise Manager

- Importing a Replay External to Enterprise Manager

- Replaying a Database Workload Using APIs

- Monitoring Workload Replay Using APIs

Tip:

Before you can replay a database workload, you must first:

- Capture the workload on the production system, as described in Capturing a Database Workload

- Preprocess the captured workload, as described in Preprocessing a Database Workload

Steps for Replaying a Database Workload

Proper preparation of the replay system and planning of the workload replay ensures that the replay will be accurate. Before replaying a database workload, complete the following steps to prepare the replay system and the workload replay:

- Setting Up the Replay Directory

- Restoring the Database

- Resolving References to External Systems

- Connection Remapping

- Specifying Replay Options

- Using Filters with Workload Replay

- Setting Up Replay Clients

Setting Up the Replay Directory

The captured workload must have been preprocessed and copied to the replay system. A directory object for the directory to which the preprocessed workload is copied must exist in the replay system.

Restoring the Database

Before a workload can be replayed, the application data state on the replay system should be logically equivalent to that of the capture system at the start time of workload capture. This minimizes replay divergence during replay. The method for restoring the database depends on the backup method that was used before capturing the workload. For example, if RMAN was used to back up the capture system, you can use RMAN DUPLICATE capabilities to create the test database. For more information, see "Prerequisites for Capturing a Database Workload".

After the database is created with the appropriate application data on the replay system, perform the system change you want to test, such as a database or operating system upgrade. The primary purpose of Database Replay is to test the effect of system changes on a captured workload. Therefore, the system changes you make should define the test you are conducting with the captured workload.

Resolving References to External Systems

A captured workload may contain references to external systems, such as database links or external tables. Typically, you should reconfigure these external interactions to avoid impacting other production systems during replay. External references that need to be resolved before replaying a workload include:

- Database links
It is typically not desirable for the replay system to interact with other databases. Therefore, you should reconfigure all database links to point to an appropriate database that contains the data needed for replay.

- External tables
All external files specified using directory objects referenced by external tables need to be available to the database during replay. The content of these files should be the same as during capture, and the filenames and directory objects used to define the external tables should also be valid.

- Directory objects
You should reconfigure any references to directories on the production system by appropriately redefining the directory objects present in the replay system after restoring the database.

- URLs
URLs/URIs that are stored in the database need to be configured so that Web services accessed during the workload capture will point to the proper URLs during replay. If the workload refers to URLs that are stored in the production system, you should isolate the test system network during replay.

- E-mails
To avoid resending E-mail notifications during replay, any E-mail server accessible to the replay system should be configured to ignore requests for outgoing E-mails.

Tip:

To avoid impacting other production systems during replay, Oracle strongly recommends running the replay within an isolated private network that does not have access to the production environment hosts.

Connection Remapping

During workload capture, connection strings used to connect to the production system are captured. In order for the replay to succeed, you need to remap these connection strings to the replay system. The replay clients can then connect to the replay system using the remapped connections.

For Oracle Real Application Clusters (Oracle RAC) databases, you can map all connection strings to a load balancing connection string. This is especially useful if the number of nodes on the replay system is different from the capture system. Alternatively, if you want to direct workload to specific instances, you can use services or explicitly specify the instance identifier in the remapped connection strings.

User Remapping

During workload capture, the username of the database user or schema used to connect to the production system is captured. You can choose to remap the captured username to that of a new user or schema.

Specifying Replay Options

After the database is restored, and connections and users are remapped, you can set the following replay options as appropriate:

- Preserving COMMIT Order

- Controlling Session Connection Rate

- Controlling Request Rate Within a Session

Preserving COMMIT Order

The synchronization parameter controls whether the COMMIT order in the captured workload will be preserved during replay.

If this parameter is set to SCN, the COMMIT order in the captured workload will be preserved during replay and all replay actions will be executed only after all dependent COMMIT actions have completed.

If this parameter is set to OBJECT_ID, all replay actions will be executed only after all relevant COMMIT actions have completed. Relevant COMMIT actions must meet the following criteria:

- Issued before the given action in the workload capture

- Modified at least one of the database objects for which the given action is referencing, either implicitly or explicitly

Setting this parameter to OBJECT_ID allows for more concurrency during workload replays for COMMIT actions that do not reference the same database objects during workload capture.

You can disable this option by setting the parameter to OFF, but the replay will likely yield significant replay divergence. However, this may be desirable if the workload consists primarily of independent transactions, and divergence during unsynchronized replay is acceptable.

Controlling Session Connection Rate

The connect_time_scale parameter enables you to scale the elapsed time between the time when the workload capture began and each session connects. You can use this option to manipulate the session connect time during replay with a given percentage value. The default value is 100, which will attempt to connect all sessions as captured. Setting this parameter to 0 will attempt to connect all sessions immediately.

Controlling Request Rate Within a Session

User think time is the elapsed time while the replayed user waits between issuing calls within a single session. To control replay speed, use the think_time_scale parameter to scale user think time during replay.

If user calls are being executed slower during replay than during capture, you can make the database replay attempt to catch up by setting the think_time_auto_correct parameter to TRUE. This will make the replay client shorten the think time between calls, so that the overall elapsed time of the replay will more closely match the captured elapsed time.

If user calls are being executed faster during replay than during capture, setting the think_time_auto_correct parameter to TRUE will not change the think time. The replay client will not increase the think time between calls to match the captured elapsed time.

Using Filters with Workload Replay

By default, all captured database calls are replayed during workload replay. You can use workload filters to specify which database calls to include in or exclude from the workload during workload replay.

Workload replay filters are first defined and then added to a replay filter set so they can be used in a workload replay. There are two types of workload filters: inclusion filters and exclusion filters. Inclusion filters enable you to specify database calls that will be replayed. Exclusion filters enable you to specify database calls that will not be replayed. You can use either inclusion filters or exclusion filters in a workload replay, but not both. The workload filter is determined as an inclusion or exclusion filter when the replay filter set is created.

Setting Up Replay Clients

The replay client is a multithreaded program (an executable named wrc located in the $ORACLE_HOME/bin directory) where each thread submits a workload from a captured session. Before replay begins, the database will wait for replay clients to connect. At this point, you need to set up and start the replay clients, which will connect to the replay system and send requests based on what has been captured in the workload.

Before starting replay clients, ensure that the:

- Replay client software is installed on the hosts where it will run

- Replay clients have access to the replay directory

- Replay directory contains the preprocessed workload capture

- Replay user has the correct user ID, password, and privileges (the replay user needs the DBA role and cannot be the SYS user)

- Replay clients are not started on a system that is running the database

- Replay clients read the capture directory on a file system that is different from the one on which the database files reside
To do this, copy the capture directory to the system where the replay client will run. After the replay is completed, you can delete the capture directory.

After these prerequisites are met, you can proceed to set up and start the replay clients using the wrc executable. The wrc executable uses the following syntax:

wrc [user/password[@server]] MODE=[value] [keyword=[value]]

The parameters user, password and server specify the username, password and connection string used to connect to the replay database. The parameter mode specifies the mode in which to run the wrc executable. Possible values include replay (the default), calibrate, and list_hosts. The parameter keyword specifies the options to use for the execution and is dependent on the mode selected. To display the possible keywords and their corresponding values, run the wrc executable without any arguments.

The following sections describe the modes that you can select when running the wrc executable:

- Calibrating Replay Clients

- Starting Replay Clients

- Displaying Host Information

Calibrating Replay Clients

Since one replay client can initiate multiple sessions with the database, it is not necessary to start a replay client for each session that was captured. The number of replay clients that need to be started depends on the number of workload streams, the number of hosts, and the number of replay clients for each host.

To estimate the number of replay clients and hosts that are required to replay a particular workload, run the wrc executable in calibrate mode.

In calibrate mode, the wrc executable accepts the following keywords:

- replaydir specifies the directory that contains the preprocessed workload capture you want to replay. If unspecified, it defaults to the current directory.

- process_per_cpu specifies the maximum number of client processes that can run per CPU. The default value is 4.

- threads_per_process specifies the maximum number of threads that can run within a client process. The default value is 50.

The following example shows how to run the wrc executable in calibrate mode:

%> wrc mode=calibrate replaydir=./replay

In this example, the wrc executable is executed to estimate the number of replay clients and hosts that are required to replay the workload capture stored in a subdirectory named replay under the current directory. In the following sample output, the recommendation is to use at least 21 replay clients divided among 6 CPUs:

Workload Replay Client: Release 12.1.0.0.1 - Production on Fri Sept 30
13:06:33 2011

Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Report for Workload in: /oracle/replay/
-----------------------

Recommendation:
Consider using at least 21 clients divided among 6 CPU(s).

Workload Characteristics:
- max concurrency: 1004 sessions
- total number of sessions: 1013

Assumptions:
- 1 client process per 50 concurrent sessions
- 4 client process per CPU
- think time scale = 100
- connect time scale = 100
- synchronization = TRUE

Starting Replay Clients

After determining the number of replay clients that are needed to replay the workload, you need to start the replay clients by running the wrc executable in replay mode on the hosts where they are installed. Once started, each replay client will initiate one or more sessions with the database to drive the workload replay.

In replay mode, the wrc executable accepts the following keywords:

- userid and password specify the user ID and password of a replay user for the replay client. If unspecified, these values default to the system user.

- server specifies the connection string that is used to connect to the replay system. If unspecified, the value defaults to an empty string.

- replaydir specifies the directory that contains the preprocessed workload capture you want to replay. If unspecified, it defaults to the current directory.

- workdir specifies the directory where the client logs will be written. This parameter is only used with the debug parameter for debugging purposes.

- debug specifies whether debug data will be created. Possible values include:

- on
Debug data will be written to files in the working directory

- off
No debug data will be written (the default value)

Note:

Before running the wrc executable in debug mode, contact Oracle Support for more information.

- connection_override specifies whether to override the connection mappings stored in the DBA_WORKLOAD_CONNECTION_MAP view. If set to TRUE, connection remappings stored in the DBA_WORKLOAD_CONNECTION_MAP view will be ignored and the connection string specified using the server parameter will be used. If set to FALSE, all replay threads will connect using the connection remappings stored in the DBA_WORKLOAD_CONNECTION_MAP view. This is the default setting.

The following example shows how to run the wrc executable in replay mode:

%> wrc system/password@test mode=replay replaydir=./replay

In this example, the wrc executable starts the replay client to replay the workload capture stored in a subdirectory named replay under the current directory.

After all replay clients have connected, the database will automatically distribute workload capture streams among all available replay clients and workload replay can begin. You can monitor the status of the replay clients using the V$WORKLOAD_REPLAY_THREAD view. After the replay finishes, all replay clients will disconnect automatically.

Displaying Host Information

You can display the hosts that participated in a workload capture and workload replay by running the wrc executable in list_hosts mode.

In list_hosts mode, the wrc executable accepts the keyword replaydir, which specifies the directory that contains the preprocessed workload capture you want to replay. If unspecified, it defaults to the current directory.

The following example shows how to run the wrc executable in list_hosts mode:

%> wrc mode=list_hosts replaydir=./replay

In this example, the wrc executable is executed to list all hosts that participated in capturing or replaying the workload capture stored in a subdirectory named replay under the current directory. In the following sample output, the hosts that participated in the workload capture and three subsequent replays are shown:

Workload Replay Client: Release 12.1.0.0.1 - Production on Fri Sept 30
13:44:48 2011

Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Hosts found:
Capture:
prod1
prod2
Replay 1:
test1
Replay 2:
test1
test2
Replay 3:
testwin

Replaying a Database Workload Using Enterprise Manager

This section describes how to replay a database workload using Enterprise Manager.

The primary tool for replaying database workloads is Oracle Enterprise Manager. If Oracle Enterprise Manager is unavailable, you can also replay database workloads using APIs, as described in "Replaying a Database Workload Using APIs".

Note:

Before proceeding, you must already have created a replay task and created a replay from the replay task. To do this, see "Preparing a Single Database Workload Using Enterprise Manager" on .

To replay a database workload using Enterprise Manager:

1. From the Enterprise menu of the Enterprise Manager Cloud Control console, select Quality Management, then Database Replay.
If the Database Login page appears, log in as a user with administrator privileges.

The Database Replay page appears.

2. Select the Replay Tasks tab, then click the link for the desired replay task in the table.
The Replay Task page for the replay appears.

3. Click Create in the Replays section to create the replay.
The Create Replay pop-up appears.

4. Provide a required Name and optional description, then click the Target Database icon.
The Search and Select: Targets pop-up appears.

5. Choose the appropriate database, then click Select.

6. Click OK in the Create Replay pop-up.
The Database Replay page for your replay appears, which includes a Task List with a link to perform the replay.

7. Click the link for the Replay Workload task.
The Replay Workload: Locate Workload page appears.

8. Select the desired workload location option.
If you have not previously copied the workload from its storage location to the replay location where the replay clients can access it, select the option to copy the workload. Otherwise, select the option to use the existing replay directory that contains the workload to be replayed.

Click Next to display the Replay Workload: Copy Workload page.

9. Provide the required credentials and the new location of the workload directory to which you want to copy the workload, then click Next.

- There are multiple source workloads for a consolidated replay, so multiple source credentials might be needed for the current location of the workload directory. For more information on consolidated replays, see "Using Consolidated Database Replay with Enterprise Manager."

The system responds by displaying a progress bar graph during processing, then displays the Replay Workload: Select Directory page after the copy operation concludes.

10. Specify the Directory Object, or create a new Directory Object that points to the location that contains the workload. If you chose to copy from the workload location to a new location in the previous step, make sure that the directory object points to the exact location you specified in the New Location of the Workload Directory section.
The system responds by displaying a Capture Summary. You can expand the Capture Details section to see the workload profile and workload filters. You can also generate a Workload Capture Analyzer Report and Database Capture Report. The Capture Summary does not appear for consolidated replays.

Click Next to display the Replay Workload: Initialize Options page.

11. In the SQL Performance Analyzer section, retain or disable the Capture SQL Statements option, which is enabled by default and recommended. You can disable this option if you do not want to compare SQL tuning sets at the end of the Replay.

- The SQL Performance Analyzer can initiate an impact analysis of environmental changes on the performance of SQL statements within a SQL Tuning Set. You can create and analyze SQL Performance Analyzer tasks to test the effects of a database upgrade, initialization parameter change, Exadata simulation, or custom experiments. A task compares the effects of before-trial changes with after-trial changes.
Although Database Replay provides an analysis of how a change affects your entire system, you can use a SQL tuning set in conjunction with the SQL Performance Analyzer to gain a more SQL-centric analysis of how the change affects SQL statements and execution plans.

By capturing a SQL tuning set during workload replay, you can use SQL Performance Analyzer to compare this SQL tuning set to another SQL tuning set captured during workload capture, without having to re-execute the SQL statements. This enables you to obtain a SQL Performance Analyzer report and compare the SQL performance, before and after change, while running Database Replay.

- In the Identify Source section, initial replay options refer to the connection mappings and parameters on the Customize Options page. Connections are captured along with the workload.

Note:

This section does not appear for consolidated replays or Oracle RAC.

Click Next to display the Replay Workload: Customize Options page.

12. Remap captured connection strings to connection strings that point to the replay system. Note that you need to remap each capture connection. For example, in the illustration above, you would need to remap the connection for both capture12_1 and capture12_adc.
(You can remap connections per workload for consolidated replay. There is a Capture Name drop-down to choose the workload.)

Click the Connection Mappings tab. There are several methods you can use to remap captured connection strings. You can choose to:

- Use a single connect descriptor for all client connections by selecting this option and entering the connect descriptor you want to use. The connect descriptor should point to the replay system.
To test the connection, click Test Connection. If the connect descriptor is valid, an Information message is displayed to inform you that the connection was successful.

- Use a single TNS net service name for all client connections by selecting this option and entering the net service name you want to use. All replay clients must be able to resolve the net service name, which can be done using a local tnsnames.ora file.

- Use a separate connect descriptor or net service name for each client connect descriptor captured in the workload by selecting this option and, for each capture system value, entering a corresponding replay system value that the replay client will be use. If you selected the "Use replay options from a previous replay" option in the Initialize Options step, the "Use a separate connect descriptor" option is selected, and the previous Replay system values appear in the text field below.

Note:

This option does not apply to consolidated replays.

For more information, see "Connection Remapping".

13. Specify the replay options using the replay parameters, which control some aspects of the Replay.
To modify the replay behavior, click the Replay Parameters tab and enter the desired values for each replay parameter. Using the default values is recommended. For information about setting the replay parameters, see "Specifying Replay Options".

After setting the replay parameters, click Next.

The Replay Workload: Prepare Replay Clients page appears.

14. Ensure that the replay clients are prepared for replay:
Before proceeding, the replay clients must be set up. For more information, see "Setting Up Replay Clients".

a. Click Estimate to determine how many Replay clients and CPUs are required for the Replay.

b. Click Add Replay Client Hosts to add a host or hosts for the Replay clients. (If you do not want to add any replay client hosts, you can still continue and start the replay clients from the command line outside of Enterprise Manager).
The Search and Select: Replay Client Host pop-up appears.

- Specify a Target Name and then click Go, or just click Go to display the entire list of available hosts.

- Choose a host and then click Select.

c. When the host name appears in the Target column of the Replay Client Hosts table, specify the number of Replay clients recommended from the estimate results, then make sure that the number of CPUs listed for the host satisfies the minimum recommendation in the estimate results. You should start at least one replay client per captured workload.

d. In the Configured column, click the No link to configure the Replay client host in the pop-up that appears.

e. Click Apply after you have finished providing input in the pop-up. The Configured column now displays Yes in the Replay Client Hosts table.

15. Click Next to start the replay clients and display the Replay Workload: Wait for Client Connections page.

For information about starting replay clients, see "Setting Up Replay Clients".

Note:

If you have reached this step in the process from the Enterprise menu, you also need to enter credentials for the replay job and for the replay result storage host.

- As replay clients are started, the replay client connections are displayed in the Client Connections table.

- The text below the clock changes if a replay client is connected.

- The Client Connections table is populated when at least one replay client is connected.

When all replay clients have connected, enter host credentials at the bottom of the page to start the replay job, then click Next to display the Replay Workload: Review page.

16. Review the options and parameters that have been defined for the workload replay.

- The value for Connected Replay Clients must be at least 1 in order to successfully submit the Replay Workload job.

- The Submit button is enabled only if at least one Replay client is connected.

17. If everything appears as you have intended, click Submit to submit the Replay job.
After the replay starts, the Home tab of the Database Replay page for this replay reappears with a system message that states "The workload replay has started."

For information about monitoring an active workload replay, see "Monitoring an Active Workload Replay".

Setting Up the Replay Schedule and Parameters Using Enterprise Manager

The Replay schedule feature enables you to scale up the instances of captured workloads to be included in a consolidated Replay, and then control the relative playback scheduling of the instances within the Replay. The relative scheduling of the captured workload instances is visually displayed by updating the alignment of the active session chart for each instance.

This feature is available for Cloud Control Database plug-in 12.1.0.5 and later releases.

This feature enables you to accomplish the following tasks:

- Offset instances so that they execute at different time intervals
You can adjust the relative replay start time of each workload instance to align the average active sessions peak times for scheduled instances of Capture workloads. This alignment of the workload peaks potentially maximizes the load on the system, so that you can experiment with how the test system responds under different workload conditions.

- Scale up the Replay workload by adding instances of the Captured workload
Each added instance is replayed independently of the other instances.

When you scale up a workload by specifying multiple instances of it, the default and recommended configuration is to replay the DML statements in one of the instances. All of the additional instances will only replay the query (ready-only) statements.

For example, if a workload has a SQL Insert to an employee database, you normally would want to have only one instance that executes the Insert, and the others would bypass user calls that modify the database with this Insert. However, you can override the default setting of an instance by unchecking the Replay Query-only check box to replay all statements in the workload.

To access the Plan Replay Schedule page:

1. From the Database Replay home page, click on the Replay Tasks tab.

2. Click on the name of an existing Replay task with more than one workload to navigate to the Replay Task page.

3. Click Create to create a new Replay.

4. Provide the requisite information in the Create Replay pop-up, then click OK.
The new Replay appears in the Replays table.

5. Click the name of your new Replay in the Replays table.
A Task List now appears in the Replay page.

6. Click the Plan Replay Schedule link.
The Plan Replay Schedule page appears.

To scale up a Replay:

1. In the drop-down next to the Add Workload Instance button, select the Capture workload for which you want to add an instance.

2. Click Add Workload Instance to add the instance.

To schedule the time intervals:

1. From the Replay Delay column, either leave the default value of 0 for the first Capture instance, or adjust the number of minutes desired before the instance starts to execute.

2. Repeat the step above for each Capture instance until you have set all of the values to represent how you want the performance spikes to execute for your testing needs.

To auto-align workload peaks:

1. Click the Auto-align button.

To specify query-only instances:

1. For each instance that you want to be query-only, enable the Replay Query-only check box.

To review the updated schedule:

1. From the Replay Task tab of the Database Replay page, click the Replay task link containing your scheduled Replay.
The Replay Task page appears.

2. Click the scheduled Replay in the Replays table.

3. Select the Review tab in the Replay page.

Monitoring Workload Replay Using Enterprise Manager

This section describes how to monitor workload replay using Enterprise Manager. The primary tool for monitoring workload replay is Oracle Enterprise Manager. Using Enterprise Manager, you can:

- Monitor or stop an active workload replay

- View a completed workload replay

If Oracle Enterprise Manager is unavailable, you can monitor workload replay using APIs and views, as described in "Monitoring Workload Replay Using APIs".

This section contains the following topics:

- Monitoring an Active Workload Replay

- Viewing a Completed Workload Replay

Monitoring an Active Workload Replay

This section describes how to monitor an active workload replay using Enterprise Manager.

To monitor an active workload replay:

1. From the Database Replay page, click the Replay Tasks tab.

2. Click the name of the replay task that contains the replay for which you want to monitor replay progress.

3. From the Replays section of the Replay Task page, click the name of the replay you have submitted for processing in the Create Replay wizard. (The Status column for this replay should show In Progress.)

The Home tab of the Database Replay page appears, and the Replay Summary shows a Status of Running.

- The replay line in the Replay Progress chart updates dynamically while the Replay is in progress. You can update the chart by clicking the Refresh button.

- The user calls line in the Replay Progress chart indicates how much of the workload the database has serviced relative to the capture at the same time.

- Data for the Replay Divergence Summary is not available until the Replay completes.

Viewing a Completed Workload Replay

This section describes how to view a completed workload replay using Enterprise Manager.

To view a completed workload replay:

1. From the Database Replay page, click the Replay Tasks tab.

2. Click the name of the replay task that contains the completed replay you want to view.

3. From the Replays section of the Replay Task page, click the name of the replay you have submitted for processing in the Create Replay wizard. (The Status column for this replay should show Completed.)

The Home tab of the Database Replay page appears, and the Replay Summary shows a Status of Completed.

- The replay line in the User Calls chart graphically represents the replay progress during the course of the entire replay from initiation to conclusion.
The chart shows how much time it has taken to replay the same workload compared to the elapsed time during the workload capture in terms of user calls. If the Replay line is above or to the left of the Capture line, the replay system is processing the workload faster than the capture system.

- Under the Replay Divergence Summary, any errors and data discrepancies between the replay system and the capture system are displayed as diverged database calls during replay. You can use the percentage of total calls that diverged as a measure of the replay quality.
To view details about the diverged calls, click the link that corresponds to the type of diverged call in the Count column to access the Diverged Calls During Replay page. The Diverged Calls During Replay page shows the most relevant set of replayed calls that diverged from the workload captured by grouping them based on common attribute values and specified filter conditions. To view details about a particular diverged call—such as the call attributes, SQL text, and bind variables—click the corresponding link in the SQL ID column to bring up the Replay Diverged Statement page.

4. To return to the Database Replay page, click the Database Replay breadcrumb.

Tip:

See Analyzing Captured and Replayed Workloads for information about accessing workload replay reports.

Importing a Replay External to Enterprise Manager

As with importing workloads external to Enterprise Manager, you can import Replays into Enterprise Manager to manage them. To import a Replay, you import it from a Replay task, which can contain one or more workloads and one or more Replays. The Replay task is at the top of the database Replay hierarchy, and serves as the container for these other subordinate components.

A Replay to be imported can be running in the test database, or the Replay can be completed and the replay directory stored on a file system.

This feature is available for Cloud Control Database plug-in 12.1.0.5 and later releases.

To import a Replay external to Enterprise Manager:

1. From the Database Replay page, click the Replay Tasks tab, then select the desired Replay task.
The Replay Task page appears.

2. Click Import in the Replays section.
The Import Replay: Source page appears

3. Select one of the three choices available to import a Replay, then click Next.

- Import one or more completed Replays from a directory in the file system
This option typically applies for a Replay created using an API, in which you now want to import it to Enterprise Manager for subsequent processing. In this case, Enterprise Manager may not be necessarily managing the Replay database.

- Import one or more completed Replays from a database target
In this case, Enterprise Manager is probably already managing the Replay database. The Replay could have been done on this database, or it could have been loaded in as would be the case for the option above.

- Attach to a Replay of this Replay task running in a database target
This option is similar to the option above, except this a Replay that is still in progress, rather than one that has already completed.

The Import Replay: Database page appears.

4. Click the search icon next to the Database Target field and select a database from the pop-up that appears.

Note:

The target version of the database reading the Replay must be at least as high as the one you used in the Replay task. For instance, if the Replay task used Oracle Database 12x, the database you select to read the Replay must be at least version 12x.

- The system now requests database and host credentials.

- In the previous step, if you chose to import one or more completed Replays from a directory in the file system, the system also requires a workload location.

- The Replay task can determine if this is a consolidated Replay based on the number of workloads contained in the Replay task. If this is a consolidated Replay, this step asks you to enter a consolidated Replay directory for the workload location.

5. Provide the requisite input for the step above, then click Next.
The Import Replay: Replay page appears.

- If you chose "Import one or more completed Replays from a directory in the file system" in step 3, this page provides a Load Replay button.

- If you chose “Import one or more completed Replays from a database target" or “Attach to a Replay of this Replay task running in a database target" in step 3, this page provides a Discover Replay button.

6. Click either Load Replay or Discover Replay, depending on which button is available in accordance with your selection in step 3.
The system displays one or more Replays, if found, in the Discovered Replays table.

7. Either click Next to load the Replay, or select one or more Replays, then click Next to continue importing the Replays.
The Import Replay: Review page appears.

8. If everything appears as you have intended, click Submit.
The Database Replay page reappears and displays a message stating that the job was submitted successfully. The Status column in the table for your imported Replay will show In Progress.

Tip:

You can check on the job's progress by clicking on the Replay name that you just submitted in the Review step. A Replay Summary page appears, and you can click the Database Replay Import Job link to see the progress of the job execution steps.

Replaying a Database Workload Using APIs

This section describes how to replay a database workload using the DBMS_WORKLOAD_REPLAY package. You can also use Oracle Enterprise Manager to replay a database workload, as described in "Replaying a Database Workload Using Enterprise Manager".

Replaying a database workload using the DBMS_WORKLOAD_REPLAY package is a multi-step process that involves:

- Initializing Replay Data

- Remapping Connections

- Setting Workload Replay Options

- Defining Workload Replay Filters and Replay Filter Sets

- Setting the Replay Timeout Action

- Starting a Workload Replay

- Pausing a Workload Replay

- Resuming a Workload Replay

- Cancelling a Workload Replay

- Retrieving Information About Workload Replays

- Loading Divergence Data for Workload Replay

- Deleting Information About Workload Replays

- Exporting AWR Data for Workload Replay

- Importing AWR Data for Workload Replay

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_WORKLOAD_REPLAY package

Initializing Replay Data

After the workload capture is preprocessed and the test system is properly prepared, the replay data can be initialized. Initializing replay data loads the necessary metadata into tables required by workload replay. For example, captured connection strings are loaded into a table where they can be remapped for replay.

To initialize replay data:

- Use the INITIALIZE_REPLAY procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.INITIALIZE_REPLAY (replay_name => 'dec06_102',
replay_dir => 'dec06');
END;
/

In this example, the INITIALIZE_REPLAY procedure loads preprocessed workload data from the dec06 directory into the database.

The INITIALIZE_REPLAY procedure in this example uses the following parameters:

- The replay_name required parameter specifies a replay name that can be used with other APIs to retrieve settings and filters of previous replays.

- The replay_dir required parameter specifies the directory that contains the workload capture that will be replayed.

See Also:

- "Preprocessing a Database Workload Using APIs" for information about preprocessing a workload capture

- "Steps for Replaying a Database Workload" for information preparing the test system

Remapping Connections

After the replay data is initialized, connection strings used in the workload capture need to be remapped so that user sessions can connect to the appropriate databases and perform external interactions as captured during replay. To view connection mappings, use the DBA_WORKLOAD_CONNECTION_MAP view. For information about connection remapping, see "Connection Remapping".

To remap connections:

- Use the REMAP_CONNECTION procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (connection_id => 101,
replay_connection => 'dlsun244:3434/bjava21');
END;
/

In this example, the connection that corresponds to the connection ID 101 will use the new connection string defined by the replay_connection parameter.

The REMAP_CONNECTION procedure in this example uses the following parameters:

- The connection_id required parameter is generated when initializing replay data and corresponds to a connection from the workload capture.

- The replay_connection required parameter specifies the new connection string that will be used during workload replay.

Remapping Users

Asides from remapping connection strings, you can also use a new schema or user instead of the user captured in the workload capture. To view captured users, use the DBA_WORKLOAD_USER_MAP view. For information about user remapping, see "User Remapping".

To remap users:

- Use the SET_USER_MAPPING procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.SET_USER_MAPPING (capture_user => 'PROD',
replay_user => 'TEST');
END;
/

In this example, the PROD user used during capture is remapped to the TEST user during replay.

The SET_USER_MAPPING procedure in this example uses the following parameters:

- The capture_user required parameter specifies the username captured during the time of the workload capture.

- The replay_user required parameter specifies the username to which the captured user is remapped during replay. If this parameter is set to NULL, then the mapping is disabled.

Setting Workload Replay Options

After the replay data is initialized, and connections and users are remapped, you need to prepare the database for workload replay. For information about workload replay preparation, see "Steps for Replaying a Database Workload".

To prepare workload replay on the replay system:

- Use the PREPARE_REPLAY procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.PREPARE_REPLAY (synchronization => OBJECT_ID,
capture_sts => TRUE,
sts_cap_interval => 300);
END;
/

In this example, the PREPARE_REPLAY procedure prepares a replay that has been previously initialized. A SQL tuning set will also be captured in parallel with the workload replay.

The PREPARE_REPLAY procedure uses the following parameters:

- The synchronization required parameter determines if synchronization will be used during workload replay.
If this parameter is set to OBJECT_ID (the default value), all replay actions will be executed only after all relevant COMMIT actions have completed. Relevant COMMIT actions must meet the following criteria:

- Issued before the given action in the workload capture

- Modified at least one of the database objects for which the given action is referencing, either implicitly or explicitly

Setting this parameter to OBJECT_ID allows for more concurrency during workload replays for COMMIT actions that do not reference the same database objects during workload capture.

If this parameter is set to SCN, the COMMIT order in the captured workload will be preserved during replay and all replay actions will be executed only after all dependent COMMIT actions have completed.

You can disable this option by setting the parameter to OFF, but the replay will likely yield significant replay divergence. However, this may be desirable if the workload consists primarily of independent transactions, and divergence during unsynchronized replay is acceptable.

- The connect_time_scale parameter scales the elapsed time from when the workload capture started to when the session connects with the specified value and is interpreted as a % value. Use this parameter to increase or decrease the number of concurrent users during replay. The default value is 100.

- The think_time_scale parameter scales the elapsed time between two successive user calls from the same session and is interpreted as a % value. Setting this parameter to 0 will send user calls to the database as fast as possible during replay. The default value is 100.

- The think_time_auto_correct parameter corrects the think time (based on the think_time_scale parameter) between calls when user calls take longer to complete during replay than during capture. This parameter can be set to either TRUE or FALSE. Setting this parameter to TRUE reduces the think time if the workload replay is taking longer than the workload capture. The default value is TRUE.

- The scale_up_multiplier parameter defines the number of times the workload is scaled up during replay. Each captured session will be replayed concurrently for as many times as specified by this parameter. However, only one session in each set of identical replay sessions will execute both queries and updates. The rest of the sessions will only execute queries.

- The capture_sts parameter specifies whether to capture a SQL tuning set in parallel with the workload replay. If this parameter is set to TRUE, you can capture a SQL tuning set during workload replay and use SQL Performance Analyzer to compare it to another SQL tuning set without having to re-execute the SQL statements. This enables you to obtain a SQL Performance Analyzer report and compare the SQL performance—before and after the change—while running Database Replay. You can also export the resulting SQL tuning set with its AWR data using the EXPORT_AWR procedure, as described in "Exporting AWR Data for Workload Replay".
This feature is not supported for Oracle RAC. Workload replay filters that are defined using DBMS_WORKLOAD_REPLAY do not apply to the SQL tuning set capture. The default value for this parameter is FALSE.

- The sts_cap_interval parameter specifies the duration of the SQL tuning set capture from the cursor cache in seconds. The default value is 300. Setting the value of this parameter below the default value may cause additional overhead with some workloads and is not recommended.

For more information about setting these parameters, see "Specifying Replay Options".

Defining Workload Replay Filters and Replay Filter Sets

This section describes how to add and remove workload replay filters, and how to create and use replay filter sets. For information about using workload filters and replay filter sets with workload replay, see "Using Filters with Workload Replay".

This section contains the following topics:

- Adding Workload Replay Filters

- Deleting Workload Replay Filters

- Creating a Replay Filter Set

- Using a Replay Filter Set

Adding Workload Replay Filters

This section describes how to add a new filter to be used in a replay filter set.

To add a new filter:

- Use the ADD_FILTER procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.ADD_FILTER (
fname => 'user_ichan',
fattribute => 'USER',
fvalue => 'ICHAN');
END;
/

In this example, the ADD_FILTER procedure adds a filter named user_ichan, which can be used to filter out all sessions belonging to the user name ICHAN.

The ADD_FILTER procedure in this example uses the following parameters:

- The fname required parameter specifies the name of the filter that will be added.

- The fattribute required parameter specifies the attribute on which the filter will be applied. Valid values include PROGRAM, MODULE, ACTION, SERVICE, USER, and CONNECTION_STRING. You must specify a valid captured connection string that will be used during replay as the CONNECTION_STRING attribute.

- The fvalue required parameter specifies the value for the corresponding attribute on which the filter will be applied. It is possible to use wildcards such as % with some of the attributes, such as modules and actions.

Once all workload replay filters are added, you can create a replay filter set that can be used when replaying the workload.

Deleting Workload Replay Filters

This section describes how to delete workload replay filters.

To delete workload replay filters:

- Use the DELETE_FILTER procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.DELETE_FILTER (fname => 'user_ichan');
END;
/

In this example, the DELETE_FILTER procedure removes the filter named user_ichan.

The DELETE_FILTER procedure in this example uses the fname required parameter, which specifies the name of the filter to be removed.

Creating a Replay Filter Set

After the workload replay filters are added, you can create a set of replay filters to use with workload replay. When creating a replay filter set, all workload replay filters that were added since the previous replay filter set was created will be used.

To create a replay filter set:

- Use the CREATE_FILTER_SET procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.CREATE_FILTER_SET (
replay_dir => 'apr09',
filter_set => 'replayfilters',
default_action => 'INCLUDE');
END;
/

In this example, the CREATE_FILTER_SET procedure creates a replay filter set named replayfilters, which will replay all captured calls for the replay stored in the apr09 directory, except for the part of the workload defined by the replay filters.

The CREATE_FILTER_SET procedure in this example uses the following parameters:

- The replay_dir parameter specifies the directory where the replay to be filtered is stored

- The filter_set parameter specifies the name of the filter set to create

- The default_action parameter determines if every captured database call should be replayed and whether the workload replay filters should be considered as inclusion or exclusion filters.
If this parameter is set to INCLUDE, all captured database calls will be replayed, except for the part of the workload defined by the replay filters. In this case, all replay filters will be treated as exclusion filters, since they will define the part of the workload that will not be replayed. This is the default behavior.

If this parameter is set to EXCLUDE, none of the captured database calls will be replayed, except for the part of the workload defined by the replay filters. In this case, all replay filters will be treated as inclusion filters, since they will define the part of the workload that will be replayed.

Using a Replay Filter Set

Once the replay filter set is created and the replay is initialized, you can use the replay filter set to filter the replay in the replay_dir directory.

To use a replay filter set:

- Use the USE_FILTER_SET procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.USE_FILTER_SET (filter_set => 'replayfilters');
END;
/

In this example, the USE_FILTER_SET procedure uses the filter set named replayfilters.

The USE_FILTER_SET procedure in this example uses the filter_set required parameter, which specifies the name of the filter set to be used in the replay.

Setting the Replay Timeout Action

This section describes how to set a timeout action for the workload replay. You can set a replay timeout action to abort user calls that are significantly slower during replay or cause a replay to hang. For example, you may want to set a replay timeout action to abort runaway queries caused by sub-optimal execution plans following a database upgrade.

When a replay timeout action is enabled, a user call will exit with an ORA-15569 error if it is delayed beyond the conditions specified by the replay timeout action. The aborted call and its error are reported as error divergence.

To set a replay timeout:

- Use the SET_REPLAY_TIMEOUT procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.SET_REPLAY_TIMEOUT (
enabled => TRUE,
min_delay => 20,
max_delay => 60,
delay_factor => 10);
END;
/

In this example, the SET_REPLAY_TIMEOUT procedure defines a replay timeout action that will abort a user call if the delay during replay is more than 60 minutes, or if the delay during replay is over 20 minutes and the elapsed time is 10 times greater than the capture elapsed time.

The SET_REPLAY_TIMEOUT procedure in this example uses the following parameters:

- The enabled parameter specifies if the replay timeout action is enabled or disabled. The default value is TRUE.

- The min_delay parameter defines the lower bound value of call delay in minutes. The replay timeout action is only activated when the delay is over this value. The default value is 10.

- The max_delay parameter defines the upper bound value of call delay in minutes. The replay timeout action is activated and issues an error when the delay is over this value. The default value is 120.

- The delay_factor parameter defines a factor for the call delays that are between the values of min_delay and max_delay. The replay timeout action issues an error when the current replay elapsed time is higher than the multiplication of the capture elapsed time and this value. The default value is 8.

To retrieve the replay timeout action setting:

- Use the GET_REPLAY_TIMEOUT procedure:

DECLARE
enabled        BOOLEAN;
min_delay      NUMBER;
max_delay      NUMBER;
delay_factor   NUMBER;
BEGIN
DBMS_WORKLOAD_REPLAY.GET_REPLAY_TIMEOUT(enabled, min_delay, max_delay,
delay_factor);
END;
/

The GET_REPLAY_TIMEOUT procedure in this example returns the following parameters:

- The enabled parameter returns whether the replay timeout action is enabled or disabled.

- The min_delay parameter returns the lower bound value of call delay in minutes.

- The max_delay parameter returns the upper bound value of call delay in minutes.

- The delay_factor parameter returns the delay factor.

Starting a Workload Replay

Before starting a workload replay, you must first:

- Preprocess the captured workload, as described in "Preprocessing a Database Workload Using APIs"

- Initialize the replay data, as described in "Initializing Replay Data"

- Specify the replay options, as described in "Setting Workload Replay Options"

- Start the replay clients, as described in "Starting Replay Clients"

Note:

Once a workload replay is started, new replay clients will not be able to connect to the database. Only replay clients that were started before the START_REPLAY procedure is executed will be used to replay the captured workload.

To start a workload replay:

- Use the START_REPLAY procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.START_REPLAY ();
END;
/

Pausing a Workload Replay

Pausing a workload replay will halt all subsequent user calls issued by the replay clients until the workload replay is either resumed or cancelled. User calls that are already in progress will be allowed to complete. This option enables you to temporarily stop the replay to perform a change and observe its impact for the remainder of the replay.

To pause a workload replay:

- Use the PAUSE_REPLAY procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.PAUSE_REPLAY ();
END;
/

Resuming a Workload Replay

This section describes how to resume a workload replay that is paused.

To resume a workload replay:

- Use the RESUME_REPLAY procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.RESUME_REPLAY ();
END;
/

Cancelling a Workload Replay

This section describes how to cancel a workload replay.

To cancel a workload replay:

- Use the CANCEL_REPLAY procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.CANCEL_REPLAY ();
END;
/

Retrieving Information About Workload Replays

You can retrieve all information about the workload captures in a replay directory object and the history of the workload replay attempts from the directory. By default, the workload replay divergence data is not loaded, but you can selectively choose to load this data.

To retrieve information about workload replays:

- Call the DBMS_WORKLOAD_REPLAY.GET_REPLAY_INFO function.
The GET_REPLAY_INFO function first imports a row into the DBA_WORKLOAD_CAPTURES view, which contains information about the workload capture. By default, it then only imports information for replays that have not been previously loaded into the DBA_WORKLOAD_REPLAYS view. This function returns the cap_id of the capture directory (for a consolidated capture directory, the cap_id returned is 0), which can be associated with the CAPTURE_ID column in the DBA_WORKLOAD_REPLAYS view to access the information retrieved.

The GET_REPLAY_INFO function uses the following parameters:

- The replay_dir required parameter, which specifies the name of the workload replay directory object.

- The load_divergence optional parameter, which specifies if divergence data is loaded. The default value for this parameter is FALSE. To load divergence data, which imports rows for every replay attempt retrieved from the replay directory into the DBA_WORKLOAD_REPLAY_DIVERGENCE view, set this parameter to TRUE. Alternatively, you can use the LOAD_DIVERGENCE procedure to selectively load divergence data for a single replay or all replays in a directory object after the replay information is retrieved, as described in "Loading Divergence Data for Workload Replay".

Example 12-1 Retrieving information about workload replay

The following example shows how to retrieve information about the workload captures and the history of the workload replay attempts for the replay directory object named jul14, and to validate that the information is retrieved.

DECLARE
cap_id         NUMBER;
BEGIN
cap_id := DBMS_WORKLOAD_REPLAY.GET_REPLAY_INFO(replay_dir => 'jul14');
SELECT capture_id
FROM dba_workload_replays
WHERE capture_id = cap_id;
END;
/

Loading Divergence Data for Workload Replay

Loading divergence data for workload replay imports rows for every replay attempt retrieved from the replay directory into the DBA_WORKLOAD_REPLAY_DIVERGENCE view, which displays information about diverged calls and errors during replay attempts. You can choose to load divergence data for either a single workload replay or all workload replays in a given directory object.

To load divergence data for workload replay:

1. Call the WORKLOAD_REPLAY.LOAD_DIVERGENCE procedure using one of the following parameters:

- The replay_id parameter specifies the ID of the workload replay for which you want to load divergence data. Use this parameter if you only want to load divergence data for a single workload replay.

- The replay_dir parameter specifies the name of the directory object (the value is case-sensitive). Use this parameter if you want to load divergence data for all workload replays in a given directory object.

2. To check the loading status of divergence data, query the DIVERGENCE_LOAD_STATUS column in the DBA_WORKLOAD_REPLAYS view.
A value of TRUE indicates that the divergence data is loaded, and a value of FALSE indicates that it has not been loaded.

Example 12-2 Loading divergence data for a single workload replay

The following example shows how to load divergence data for the workload replay with a replay_id value of 12, and to validate that the divergence data is loaded.

DECLARE
rep_id         NUMBER;
BEGIN
rep_id := DBMS_WORKLOAD_REPLAY.LOAD_DIVERGENCE (replay_id => 12);
SELECT divergence_load_status
FROM dba_workload_replays
WHERE capture_id = rep_id;
END;
/

Deleting Information About Workload Replays

You can delete information retrieved for either a single workload replay or all workload replays in a given directory object. Deleted information can be retrieved using the GET_REPLAY_INFO function, as described in "Retrieving Information About Workload Replays".

Alternatively, you can also choose to permanently delete the replay data from disk. Doing so will prevent retrieval of the deleted data.

To delete information about workload replays:

1. Call the DBMS_WORKLOAD_REPLAY.DELETE_REPLAY_INFO procedure using one of the following parameters.

- The replay_id parameter specifies the ID of the workload replay for which you want to delete replay information. Use this parameter if you only want to delete information for a single workload replay.

- The replay_dir parameter specifies the name of the directory object (the value is case-sensitive). Use this parameter if you want to delete information for all workload replays in a given directory object.

2. By default, deleting information about workload replays does not remove the data from disk.
To delete the replay data from disk and prevent retrieval of the deleted data, set the value of the permanent parameter to TRUE (the default value is FALSE).

Example 12-3 Deleting information about workload replay

The following example deletes information retrieved about the workload captures and the history of the workload replay attempts for the replay directory object named jul14. The replay data is not deleted from disk, and thus can be retrieved by calling the GET_REPLAY_INFO function, as described in "Retrieving Information About Workload Replays".

BEGIN
DBMS_WORKLOAD_REPLAY.DELETE_REPLAY_INFORMATION (replay_dir => 'jul14');
END;
/

Exporting AWR Data for Workload Replay

Exporting AWR data enables detailed analysis of the workload. This data is also required if you plan to run the AWR Compare Period report on a pair of workload captures or replays.

To export AWR data:

- Use the EXPORT_AWR procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.EXPORT_AWR (replay_id => 1);
END;
/

In this example, the AWR snapshots that correspond to the workload replay with a replay ID of 1 are exported, along with any SQL tuning set that may have been captured during workload replay.

The EXPORT_AWR procedure uses the replay_id required parameter, which specifies the ID of the replay whose AWR snapshots will be exported.

Note:

This procedure works only if the corresponding workload replay was performed in the current database and the AWR snapshots that correspond to the original replay time period are still available.

Importing AWR Data for Workload Replay

After AWR data is exported from the replay system, you can import the AWR data into another system. Importing AWR data enables detailed analysis of the workload. This data is also required if you plan to run the AWR Compare Period report on a pair of workload captures or replays.

To import AWR data:

- Use the IMPORT_AWR function:

CREATE USER capture_awr
SELECT DBMS_WORKLOAD_REPLAY.IMPORT_AWR (replay_id => 1,
staging_schema => 'capture_awr')
FROM DUAL;

In this example, the AWR snapshots that correspond to the workload replay with a capture ID of 1 are imported using a staging schema named capture_awr.

The IMPORT_AWR procedure in this example uses the following parameters:

- The replay_id required parameter specifies the ID of the replay whose AWR snapshots will be import.

- The staging_schema required parameter specifies the name of a valid schema in the current database which can be used as a staging area while importing the AWR snapshots from the replay directory to the SYS AWR schema.

Note:

This function fails if the schema specified by the staging_schema parameter contains any tables with the same name as any of the AWR tables.

Monitoring Workload Replay Using APIs

This section describes how to monitor workload replay using APIs and views. You can also use Oracle Enterprise Manager to monitor workload replay, as described in "Monitoring Workload Replay Using Enterprise Manager".

This section contains the following topics:

- Retrieving Information About Diverged Calls

- Monitoring Workload Replay Using Views

Retrieving Information About Diverged Calls

During replay, any error and data discrepancies between the replay system and the capture system are recorded as diverged calls.

To retrieve information about a diverged call—including its SQL identifier, SQL text, and bind values—call the GET_DIVERGING_STATEMENT function using the following parameters:

- Set the replay_id parameter to the ID of the replay in which the call diverged

- Set the stream_id parameter to the stream ID of the diverged call

- Set the call_counter parameter to the call counter of the diverged call

To view these information about a diverged call, use the DBA_WORKLOAD_REPLAY_DIVERGENCE view. The following example illustrates a function call:

DECLARE
r                   CLOB;
ls_stream_id        NUMBER;
ls_call_counter     NUMBER;
ls_sql_cd           VARCHAR2(20);
ls_sql_err          VARCHAR2(512);
CURSOR c IS
SELECT stream_id, call_counter
FROM DBA_WORKLOAD_REPLAY_DIVERGENCE
WHERE replay_id = 72;
BEGIN
OPEN c;
LOOP
FETCH c INTO ls_stream_id, ls_call_counter;
EXIT when c%notfound;
DBMS_OUTPUT.PUT_LINE (ls_stream_id||''||ls_call_counter);
r:=DBMS_WORKLOAD_REPLAY.GET_DIVERGING_STATEMENT(replay_id => 72,
stream_id => ls_stream_id, call_counter => ls_call_counter);
DBMS_OUTPUT.PUT_LINE (r);
END LOOP;
END;
/

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_WORKLOAD_REPLAY package

Monitoring Workload Replay Using Views

This section summarizes the views that you can display to monitor workload replay. You need DBA privileges to access these views.

- The DBA_WORKLOAD_CAPTURES view lists all the workload captures that have been captured in the current database.

- The DBA_WORKLOAD_FILTERS view lists all workload filters for workload captures defined in the current database.

- The DBA_WORKLOAD_REPLAYS view lists all the workload replays that have been replayed in the current database.

- The DBA_WORKLOAD_REPLAY_DIVERGENCE view enables you to view information about diverged calls, such as the replay identifier, stream identifier, and call counter.

- The DBA_WORKLOAD_REPLAY_FILTER_SET view lists all workload filters for workload replays defined in the current database.

- The DBA_WORKLOAD_CONNECTION_MAP view lists the connection mapping information for workload replay.

- The V$WORKLOAD_REPLAY_THREAD view lists information about all sessions from the replay clients.

See Also:

- Oracle Database Reference for information about these views

13 Analyzing Captured and Replayed Workloads

This chapter describes how to analyze captured and replayed workloads using various Database Replay reports:

- Workload capture reports
Workload capture reports display information about captured workloads. See "Using Workload Capture Reports".

- Workload replay reports
Workload replay reports measure performance differences between the capture system and the replay system. See "Using Workload Replay Reports".

- Replay compare period reports
Replay compare period reports compare a workload replay to its capture, or to another replay of the same capture. If you are using Consolidated Database Replay, this report also compares multiple workload captures to a consolidated replay. See "Using Replay Compare Period Reports".

- SQL Performance Analyzer reports
SQL Performance Analyzer reports compare a SQL tuning set from a workload replay to one from its workload capture, or two SQL tuning sets from two workload replays. See "Using SQL Performance Analyzer Reports".

Note:

After the replay analysis is complete, you can restore the database to its original state at the time of workload capture and repeat workload replay to test other changes to the system once the workload directory object is backed up to another physical location.

Using Workload Capture Reports

Workload capture reports contain captured workload statistics, information about the top session activities that were captured, and any workload filters used during the capture process.

The following sections describe how to generate and utilize workload capture reports:

- Accessing Workload Capture Reports Using Enterprise Manager

- Generating Workload Capture Reports Using APIs

- Reviewing Workload Capture Reports

Accessing Workload Capture Reports Using Enterprise Manager

This section describes how to generate a workload capture report using Oracle Enterprise Manager.

The primary tool for generating workload capture reports is Oracle Enterprise Manager. If for some reason Oracle Enterprise Manager is unavailable, you can generate workload capture reports using APIs, as described in "Generating Workload Capture Reports Using APIs".

To access workload capture reports using Enterprise Manager:

1. From the Enterprise menu of the Enterprise Manager Cloud Control console, select Quality Management, then Database Replay.

If the Database Login page appears, log in as a user with administrator privileges.

The Database Replay page appears.

2. From the Captured Workloads tab of the Database Replay page for a capture that has a Status other than Completed, click the name of the desired capture from the Capture table.

The Summary tab of the Database Replay page appears.

3. Click the Reports tab for access to controls for the Workload Capture report and Workload Capture ASH Analytics report.

- The Workload Capture report contains detailed output showing the type of data components that were captured and not captured.

For information about how to interpret the workload capture report, see "Reviewing Workload Capture Reports".

- The Capture ASH Analytics report shows which sessions are consuming the most database time. This report provides a stacked chart to help you visualize the active session activity for several dimensions, such as Event, Activity Class, Module/Action, Session, Instance ID, and PL/SQL function.
The "Other Activity" list choice for the report means that the activity has not been captured.

4. After you access a report, you can save it by clicking Save.

See Also:

- Oracle Database Performance Tuning Guide for information about ASH (Active Session History).

Generating Workload Capture Reports Using APIs

You can generate a workload capture report using the DBMS_WORKLOAD_CAPTURE package. You can also use Oracle Enterprise Manager to generate a workload capture report, as described in "Accessing Workload Capture Reports Using Enterprise Manager".

To generate a report on the latest workload capture:

1. Use the DBMS_WORKLOAD_CAPTURE.GET_CAPTURE_INFO procedure.
The GET_CAPTURE_INFO procedure retrieves all information regarding the workload capture and returns the cap_id for the workload capture. This function uses the dir required parameter, which specifies the name of the workload capture directory object.

2. Call the DBMS_WORKLOAD_CAPTURE.REPORT function.
The REPORT function generates a report using the cap_id that was returned by the GET_CAPTURE_INFO procedure. This function uses the following parameters:

- The capture_id required parameter relates to the directory that contains the workload capture for which the report will be generated. The directory should be a valid directory in the host system containing the workload capture. The value of this parameter should match the cap_id returned by the GET_CAPTURE_INFO procedure.

- The format required parameter specifies the report format. Valid values include DBMS_WORKLOAD_CAPTURE.TYPE_TEXT and DBMS_WORKLOAD_REPLAY.TYPE_HTML.

In this example, the GET_CAPTURE_INFO procedure retrieves all information regarding the workload capture in the jul14 directory and returns the cap_id for the workload capture. The REPORT function then generates a text report using the cap_id that was returned by the GET_CAPTURE_INFO procedure.

DECLARE
cap_id         NUMBER;
cap_rpt        CLOB;
BEGIN
cap_id  := DBMS_WORKLOAD_CAPTURE.GET_CAPTURE_INFO(dir => 'jul14');
cap_rpt := DBMS_WORKLOAD_CAPTURE.REPORT(capture_id => cap_id,
format => DBMS_WORKLOAD_CAPTURE.TYPE_TEXT);
END;
/

For information about how to interpret the workload capture report, see "Reviewing Workload Capture Reports".

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_WORKLOAD_CAPTURE package

Reviewing Workload Capture Reports

The workload capture report contains various types of information that can be used to assess the validity of the workload capture. Using the information provided in this report, you can determine if the captured workload:

- Represents the actual workload you want to replay

- Does not contain any workload you want to exclude

- Can be replayed

The information contained in the workload capture report is divided into the following categories:

- Details about the workload capture (such as the name of the workload capture, defined filters, date, time, and SCN of capture)

- Overall statistics about the workload capture (such as the total DB time captured, and the number of logins and transactions captured) and the corresponding percentages with respect to total system activity

- Profile of the captured workload

- Profile of the uncaptured workload due to version limitations

- Profile of the uncaptured workload that was excluded using defined filters

- Profile of the uncaptured workload that consists of background process or scheduled jobs

Using Workload Replay Reports

Workload replay reports contain information that can be used to measure performance differences between the capture system and the replay system.

The following sections describe how to generate and review workload replay reports:

- Accessing Workload Replay Reports Using Enterprise Manager

- Generating Workload Replay Reports Using APIs

- Reviewing Workload Replay Reports

Accessing Workload Replay Reports Using Enterprise Manager

This section describes how to generate a workload replay report using Oracle Enterprise Manager.

The primary tool for generating workload replay reports is Oracle Enterprise Manager. If for some reason Oracle Enterprise Manager is unavailable, you can generate workload replay reports using APIs, as described in "Generating Workload Replay Reports Using APIs"

To access workload replay reports using Enterprise Manager:

1. From the Enterprise menu of the Enterprise Manager Cloud Control console, select Quality Management, then Database Replay.

If the Database Login page appears, log in as a user with administrator privileges.

The Database Replay page appears.

2. Click the Replay Tasks tab, then select a replay for which you want to access reports.

3. Click the Reports tab to gain access to individual reports.

There are several types of reports you can view for a completed workload replay:

- Database Replay
Use this report to view complete replay statistics in a tabular format, including replay divergence and the workload profile.

- Compare Period ADDM
Use this report to perform a high-level comparison of one workload replay to its capture or to another replay of the same capture. Only workload replays that contain at least 5 minutes of database time can be compared using this report.

Examine the following sections of the report to understand the performance change between the two periods and the cause of the change:

- Overview
This portion of the report shows SQL commonality, which is the comparability between the base and comparison periods based on the average resource consumption of the SQL statements common to both periods.

A commonality value of 100% means that the workload "signature" in both time periods is identical. A commonality of 100% is expected for this use case, because the workload being replayed is the same (assuming that you are not using replay filters). A value of 0% means that the two time periods have no items in common for the specific workload dimension.

Commonality is based on the type of input (that is, which SQL is executing) as well as the load of the executing SQL statements. Consequently, SQL statements running in only one time period, but not consuming significant time, do not affect commonality. Therefore, two workloads could have a commonality of 100% even if some SQL statements are running only in one of the two periods, provided that these SQL statements do not consume significant resources.

- Configuration
The information displayed shows base period and comparison period values for various parameters categorized by instance, host, and database.

- Findings
The findings can show performance improvements and identify the major performance differences caused by system changes. For negative outcomes, if you understand and remove the cause, the negative outcome can be eliminated.

The values shown for the Base Period and Comparison Period represent performance with regard to database time.

The Change Impact value represents a measurement of the scale of a change in performance from one time period to another. It is applicable to issues or items measured by the total database time they consumed in each time period. The absolute values are sorted in descending order.

If the value is positive, an improvement has occurred, and if the value is negative, a regression has occurred. For instance, a change impact of -200% means that period 2 is three times as slow as period 1.

You can run performance tuning tools, such as ADDM and the SQL Tuning Advisor, to fix issues in the comparison period to improve general system performance.

- Resources
The information shown provides a summary of the division of database time for both time periods, and shows the resource usage for CPU, memory, I/O, and interconnect (Oracle RAC only).

- SQL Performance Analyzer
Use this report to compare a SQL tuning set from a workload capture to another SQL tuning set from a workload replay, or two SQL tuning sets from two workload replays. Comparing SQL tuning sets with Database Replay provides more information than SQL Performance Analyzer test-execute, because it considers and shows all execution plans for each SQL statement, while SQL Performance Analyzer test-execute generates only one execution plan per SQL statement for each SQL trial.

- Replay Compare Period
Use this report to compare the AWR data from one workload replay to its capture or to another replay of the same capture. Before running this report, AWR data for the captured or replayed workload must have been previously exported.

For information about using this report, see "Reviewing Replay Compare Period Reports". For information about how to interpret replay compare period reports, see Oracle Database 2 Day + Performance Tuning Guide.

- Replay ASH Analytics
The Replay ASH Analytics report contains active session history (ASH) information for a specified duration of a workload that was replayed for the category you selected in the drop-down menu. Before running this report, AWR data must have been previously exported from the captured or replayed workload.

The chart shows workload activity breakdown values for wait classes, and provides detailed statistics for the top activity sessions that are adversely affecting the system.

You can optionally use the Load Map for a graphical view of system activity. The Load Map is useful for viewing activity in a single- or multi-dimensional layout when you are not interested in seeing how activity has changed over time within the selected period.

For more information about this report, see the Oracle Database 2 Day + Performance Tuning Guide.

Generating Workload Replay Reports Using APIs

You can generate a workload replay report using the DBMS_WORKLOAD_REPLAY package. You can also use Oracle Enterprise Manager to generate a workload replay report, as described in "Accessing Workload Replay Reports Using Enterprise Manager".

To generate a report on the latest workload replay for a workload capture using APIs:

1. Retrieve information about the workload captures and the history of the workload replay attempts from the replay directory object by calling the DBMS_WORKLOAD_REPLAY.GET_REPLAY_INFO function, as described in "Retrieving Information About Workload Replays".
The GET_REPLAY_INFO function returns the cap_id of a single capture directory (for a consolidated capture directory, the cap_id returned is 0).

2. Using the cap_id that was returned by the GET_REPLAY_INFO function, run a query to return the appropriate rep_id for the latest replay of the workload.

3. Call the DBMS_WORKLOAD_REPLAY.REPORT function.
The REPORT function generates a report using the rep_id that was returned by the SELECT statement.

The REPORT function uses the following parameters:

- The replay_id required parameter specifies the directory that contains the workload replay for which the report will be generated. The directory should be a valid directory in the host system containing the workload replay. The value of this parameter should match the rep_id returned by the previous query.

- The format parameter required parameter specifies the report format. Valid values include DBMS_WORKLOAD_REPLAY.TYPE_TEXT, DBMS_WORKLOAD_REPLAY.TYPE_HTML, and DBMS_WORKLOAD_REPLAY.TYPE_XML.

In this example, the GET_REPLAY_INFO function retrieves all information about the workload captures and the history of all the workload replay attempts from the jul14 replay directory object. The function returns the cap_id of the capture directory, which can be associated with the CAPTURE_ID column in the DBA_WORKLOAD_REPLAYS view to access the information retrieved.The SELECT statement returns the appropriate rep_id for the latest replay of the workload. The REPORT function then generates a HTML report using the rep_id that was returned by the SELECT statement.

DECLARE
cap_id         NUMBER;
rep_id         NUMBER;
rep_rpt        CLOB;
BEGIN
cap_id := DBMS_WORKLOAD_REPLAY.GET_REPLAY_INFO(replay_dir => 'jul14');
/* Get the latest replay for that capture */
SELECT max(id)
INTO   rep_id
FROM   dba_workload_replays
WHERE  capture_id = cap_id;

rep_rpt := DBMS_WORKLOAD_REPLAY.REPORT(replay_id => rep_id,
format => DBMS_WORKLOAD_REPLAY.TYPE_HTML);
END;
/

For information about how to interpret the workload replay report, see "Reviewing Workload Replay Reports".

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_WORKLOAD_REPLAY package

Reviewing Workload Replay Reports

After the workload is replayed on a test system, there may be some divergence in what is replayed compared to what was captured. There are numerous factors that can cause replay divergence, which can be analyzed using the workload replay report. The information contained in the workload replay report consists of performance and replay divergence.

Performance divergence may result when new algorithms are introduced in the replay system that affect the overall performance of the database. For example, if the workload is replayed on a newer version of Oracle Database, a new algorithm may cause specific requests to run faster, and the divergence will appear as a faster execution. In this case, this is a desirable divergence.

Data divergence occurs when the results of DML or SQL queries do not match results that were originally captured in the workload. For example, a SQL statement may return fewer rows during replay than those returned during capture.

Error divergence occurs when a replayed database call:

- Encounters a new error that was not captured

- Does not encounter an error that was captured

- Encounters a different error from what was captured

The information contained in the workload replay report is divided into the following categories:

- Details about the workload replay and the workload capture, such as job name, status, database information, duration and time of each process, and the directory object and path

- Replay options selected for the workload replay and the number of replay clients that were started

- Overall statistics about the workload replay and the workload capture (such as the total DB time captured and replayed, and the number of logins and transactions captured and replayed) and the corresponding percentages with respect to total system activity

- Profile of the replayed workload

- Replay divergence

- Error divergence

- DML and SQL query data divergence

Using Replay Compare Period Reports

Use replay compare period reports to compare the performance of:

- A workload replay to its workload capture

- A workload replay to another replay of the same workload capture

- Multiple workload captures to a consolidated replay

The following sections describe how to generate and review replay compare period reports:

- Generating Replay Compare Period Reports Using APIs

- Reviewing Replay Compare Period Reports

See Also:

- Using Consolidated Database Replay for information about Consolidated Database Replay

Generating Replay Compare Period Reports Using APIs

This section describes how to generate replay compare period reports using the DBMS_WORKLOAD_REPLAY package. This report only compares workload replays that contain at least 5 minutes of database time.

To generate replay compare period reports, use the DBMS_WORKLOAD_REPLAY.COMPARE_PERIOD_REPORT procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.COMPARE_PERIOD_REPORT (
replay_id1 => 12,
replay_id2 => 17,
format => DBMS_WORKLOAD_CAPTURE.TYPE_HTML,
result => :report_bind);
END;
/

In this example, the COMPARE_PERIOD_REPORT procedure generates a replay compare period report in HTML format that compares a workload replay with a replay ID of 12 with another replay with an ID of 17.

The COMPARE_PERIOD_REPORT procedure in this example uses the following parameters:

- The replay_id1 parameter specifies the numerical identifier of the workload replay after change for which the reported will be generated. This parameter is required.

- The replay_id2 parameter specifies the numerical identifier of the workload replay before change for which the reported will be generated. If unspecified, the comparison will be performed with the workload capture.

- The format parameter specifies the report format. Valid values include DBMS_WORKLOAD_CAPTURE.TYPE_HTML for HTML and DBMS_WORKLOAD_CAPTURE.TYPE_XML for XML. This parameter is required.

- The result parameter specifies the output of the report.

For information about how to interpret the replay compare period report, see "Reviewing Replay Compare Period Reports".

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_WORKLOAD_REPLAY package

Reviewing Replay Compare Period Reports

Reviewing replay compare period reports enables you to determine if any replay divergence occurred and whether there were any significant performance changes.

Depending on the type of comparison that is being made, one of three types of replay compare period reports is generated:

- Capture vs. Replay
This report type compares the performance of a workload replay to its workload capture.

- Replay vs. Replay
This report type compares the performance of two workload replays of the same workload capture.

- Consolidated Replay
This report type compares the performance of multiple workload captures to a consolidated replay. Only the ASH Data Comparison section is available for this report type. For more information about this report type, see "Reporting and Analysis for Consolidated Database Replay".

All replay compare period report types contain information about the most important changes between the two runs that are being compared. Use this information to determine the appropriate action to take. For example, if a new concurrency issue is found, review Automatic Database Diagnostic Monitor (ADDM) reports to diagnose the issue. If a new SQL performance problem is found, run SQL Tuning Advisor to fix the problem.

The information in the replay compare period report is divided into the following sections:

- General Information

- Replay Divergence

- Main Performance Statistics

- Top SQL/Call

- Hardware Usage Comparison

- ADDM Comparison

- ASH Data Comparison

General Information

This section contains metadata about the two runs being compared in the report. Any init.ora parameter changes between the two runs are also shown here. Review this section to verify if the system change being tested was performed.

Replay Divergence

This section contains the divergence analysis of the second run relative to the first. If the analysis shows significant divergence, review the full divergence report.

Main Performance Statistics

This section contains a high-level performance statistic comparison across the two runs (such as change in database time). If the comparison shows an insignificant change in database time, then the performance between the two runs are generally similar. If there is a significant change in database time, review the statistics to determine the component (CPU or user I/O) that is causing the greatest change.

Top SQL/Call

This section compares the performance change of individual SQL statements from one run to the next. The SQL statements are ordered by the total change in database time. Top SQL statements that regressed by the most database time are best candidates for SQL tuning.

Hardware Usage Comparison

This section compares CPU and I/O usage across the two runs. The number of CPUs is summed for all instances and CPU usage is averaged over instances.

I/O statistics are shown for data and temp files. A high value for the single block read time (much higher than 10 milliseconds) suggests that the system is I/O bound. If this is the case, then review the total read and write times to determine if the latency is caused by excessive I/O requests or poor I/O throughput.

ADDM Comparison

This section contains a comparison of ADDM analyses across the two runs ordered by the absolute difference in impact. Compare the ADDM results for the two runs to identify possible problems that only existed in one run. If the system change being tested is intended to improve database performance, then verify if the expected improvement is reflected in the ADDM findings.

See Also:

- Oracle Database Performance Tuning Guide for information about ADDM analysis

ASH Data Comparison

This section compares the ASH data across the two runs. The begin time and end time of the comparison period are displayed in a table. These times may not match the capture and replay times of the two runs being compared. Instead, these times represent the times when the ASH samples were taken.

The ASH Data Comparison section contains the following subsections:

- Compare Summary

- Top SQL

- Long Running SQL

- Common SQL

- Top Objects

See Also:

- Oracle Database Performance Tuning Guide for information about ASH

Compare Summary

This section summarizes the activity during the two runs based on database time and wait time distribution:

- DB Time Distribution indicates how the total database time is distributed across CPU usage, wait times, and I/O requests.
Figure 13-1 shows the DB Time Distribution subsection of a sample report.

Figure 13-1 DB Time Distribution

- Wait Time Distribution indicates how the total wait time is distributed across wait events. The top wait event class, event name, and event count are listed for both runs.
Figure 13-2 shows the Wait Time Distribution subsection of a sample report.

Figure 13-2 Wait Time Distribution

Top SQL

This section displays the top SQL statements for both runs by total database time, CPU time, and wait time.

Long Running SQL

This section displays the top long-running SQL statements for both runs. Each long-running SQL statement contains details about the query, such as the maximum, minimum, and average response times.

Common SQL

This section extracts the SQL statements that are common in both runs and displays the top common SQL statements by variance in average response time and total database time.

Top Objects

This section contains details about the top objects for both runs by total wait time.

Figure 13-3 shows the Top Objects section of a sample report.

Figure 13-3 Top Objects

Using SQL Performance Analyzer Reports

Use the SQL Performance Analyzer report to compare a SQL tuning set from a workload replay to another SQL tuning set from a workload capture, or two SQL tuning sets from two workload replays.

Comparing SQL tuning sets with Database Replay provides more information than SQL Performance Analyzer test-execute because it considers and shows all execution plans for each SQL statement, while SQL Performance Analyzer test-execute generates only one execution plan per SQL statement for each SQL trial.

Generating SQL Performance Analyzer Reports Using APIs

This section describes how to generate a SQL Performance Analyzer report using the DBMS_WORKLOAD_REPLAY package.

To generate a SQL Performance Analyzer report, use the DBMS_WORKLOAD_REPLAY.COMPARE_SQLSET_REPORT procedure:

BEGIN
DBMS_WORKLOAD_REPLAY.COMPARE_SQLSET_REPORT (
replay_id1 => 12,
replay_id2 => 17,
format => DBMS_WORKLOAD_CAPTURE.TYPE_HTML,
result => :report_bind);
END;
/

In this example, the COMPARE_SQLSET_REPORT procedure generates a SQL Performance Analyzer report in HTML format that compares a SQL tuning set captured during the workload replay with a replay ID of 12 to a SQL tuning set captured during workload replay with an ID of 17.

The COMPARE_SQLSET_REPORT procedure in this example uses the following parameters:

- The replay_id1 parameter specifies the numerical identifier of the workload replay after change for which the reported will be generated. This parameter is required.

- The replay_id2 parameter specifies the numerical identifier of the workload replay after change for which the reported will be generated. If unspecified, the comparison will be performed with the workload capture.

- The format parameter specifies the report format. Valid values include DBMS_WORKLOAD_CAPTURE.TYPE_HTML for HTML, DBMS_WORKLOAD_CAPTURE.TYPE_XML for XML, and DBMS_WORKLOAD_CAPTURE.TYPE_TEXT for text. This parameter is required.

- The result parameter specifies the output of the report.

For information about how to interpret the SQL Performance Analyzer report, see "Reviewing the SQL Performance Analyzer Report in Command-Line" .

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_WORKLOAD_REPLAY package

14 Using Workload Intelligence

Workload Intelligence analyzes the data stored in a captured workload and identifies significant patterns in a workload. This chapter describes how to use Workload Intelligence and contains the following sections:

- Overview of Workload Intelligence

- Analyzing Captured Workloads Using Workload Intelligence

- Example: Workload Intelligence Results

Overview of Workload Intelligence

Workload capture generates a number of binary files—called capture files—that contain relevant information about the captured workload. The information stored in the capture files enables workload replay to realistically reproduce the captured workload at a later time. For each client request that is recorded by workload capture, the captured information includes SQL text, bind values, transaction information, timing data, identifiers of accessed objects, and other information about the request.

Workload Intelligence enables you to use the information stored in capture files in additional ways, including the following:

- Analyze and model the workload

- Discover significant patterns and trends within the workload

- Visualize what was running on the production system during workload capture

This section describes Workload Intelligence and contains the following topics:

- About Workload Intelligence

- Use Case for Workload Intelligence

- Requirements for Using Workload Intelligence

See Also:

- "Workload Capture" for information about workload capture

- "Workload Replay" for information about workload replay

About Workload Intelligence

Workload Intelligence comprises a suite of Java programs that enable you to analyze the data stored in a captured workload. These Java programs operate on data recorded during a workload capture to create a model that describes the workload. This model can help you identify significant patterns of templates that are executed as part of the workload.

A template represents a read-only SQL statement, or an entire transaction that consists of one or more SQL statements. If two SQL statements (or transactions) exhibit significant similarity, then they are represented by the same template.

Workload Intelligence enables you to better visualize what a captured workload looks like by exploring template patterns and the corresponding SQL statements. For each pattern, you can view important statistics, such as the number of executions of a given pattern and the database time consumed by the pattern during its execution.

Use Case for Workload Intelligence

SQL statements that are executed in a production system are typically not manually inputted by the users, but instead come from one or more applications running on an application server that is connected to the database server. There is usually a finite number of such SQL statements in an application. Even if different bind values are used in every execution of a particular statement, its SQL text essentially remains the same.

Depending on the user input to the application, a code path is executed that includes one or more SQL statements submitted to the database in a given order as defined by the application code. Frequent user actions correspond to application code paths that are regularly executed. Such frequently executed code paths generate a frequent pattern of SQL statements that are executed by the database in a given order. By analyzing a captured workload, Workload Intelligence discovers such patterns and associates them with related execution statistics. In other words, Workload Intelligence uses the information stored in capture files to discover patterns that are generated by significant code paths of applications running in the production system during workload capture. Workload Intelligence does this without requiring any information about the applications.

Using Workload Intelligence to discover significant patterns:

- Enables you to better visualize what was running in the database during workload capture.

- Provides more information that can be used for optimizations.

- Offers a better context because SQL statements are not isolated, but are combined.

Requirements for Using Workload Intelligence

Workload Intelligence uses the information that is stored in the capture files, and does not require the execution of the workload using workload replay. Furthermore, Workload Intelligence does not require any user schema, user data, or connection to the production system. To avoid any overhead in the production system, it is recommended that Workload Intelligence be used on a test system where the capture files have been copied, especially for large captured workloads because running Workload Intelligence may be resource intensive.

The necessary Java classes for invoking the Java programs that comprise Workload Intelligence are packed in $ORACLE_HOME/rdbms/jlib/dbrintelligence.jar. Two other jar files must be included in the classpath: $ORACLE_HOME/rdbms/jlib/dbrparser.jar and $ORACLE_HOME/jdbc/lib/ojdbc6.jar.

Workload Intelligence also uses some SYS tables and views internally.

Analyzing Captured Workloads Using Workload Intelligence

This section describes the steps in using Workload Intelligence.

To analyze captured workloads using Workload Intelligence:

1. Create a database user with the appropriate privileges to use Workload Intelligence, as described in "Creating a Database User for Workload Intelligence".

2. Create a new Workload Intelligence job by running the LoadInfo Java program, as described in "Creating a Workload Intelligence Job".

3. Generate a model that describes the workload by running the BuildModel Java program, as described in "Generating a Workload Model".

4. Identify patterns in templates that occur in the workload by running the FindPatterns Java program, as described in "Identifying Patterns in a Workload".

5. Generate a report to display the results by running the GenerateReport Java program, as described in "Generating a Workload Intelligence Report".

Creating a Database User for Workload Intelligence

Before using Workload Intelligence, first create a database user with the appropriate privileges.

Example 14-1 shows how to create a database user that can use Workload Intelligence.

Example 14-1 Creating a Database User for Workload Intelligence

create user workintusr identified by password;
grant create session to workintusr;
grant select,insert,alter on WI$_JOB to workintusr;
grant insert,alter on WI$_TEMPLATE to workintusr;
grant insert,alter on WI$_STATEMENT to workintusr;
grant insert,alter on WI$_OBJECT to workintusr;
grant insert,alter on WI$_CAPTURE_FILE to workintusr;
grant select,insert,alter on WI$_EXECUTION_ORDER to workintusr;
grant insert,update,delete,alter on WI$_FREQUENT_PATTERN to workintusr;
grant insert,delete,alter on WI$_FREQUENT_PATTERN_ITEM to workintusr;
grant insert,delete,alter on WI$_FREQUENT_PATTERN_METADATA to workintusr;
grant select on WI$_JOB_ID to workintusr;
grant execute on DBMS_WORKLOAD_REPLAY to workintusr;

Creating a Workload Intelligence Job

To create a Workload Intelligence job, use the LoadInfo program. LoadInfo is a Java program that creates a new task to apply the algorithms of Workload Intelligence. The program parses the data contained in a capture directory and stores the relevant information required for running Workload Intelligence in internal tables.

The LoadInfo program uses the following syntax:

java oracle.dbreplay.workload.intelligence.LoadInfo -cstr connection_string -user username -job job_name -cdir capture_directory

java oracle.dbreplay.workload.intelligence.LoadInfo -version

java oracle.dbreplay.workload.intelligence.LoadInfo -usage

The LoadInfo program supports the following options:

- -cstr
Specifies the JDBC connection string to the database where Workload Intelligence stores the information and intermediate results required for execution (for example, jdbc:oracle:thin@hostname:portnum:ORACLE_SID)

- -user
Specifies the database username. The user must have certain privileges for using Workload Intelligence.

For information about creating a database user with the appropriate privileges, see "Creating a Database User for Workload Intelligence".

- -job
Specifies a name that uniquely identifies the Workload Intelligence job.

- -cdir
Specifies the operating system path of the capture directory to be analyzed by Workload Intelligence.

- -version
Displays the version information for the LoadInfo program.

- -usage
Displays the command-line options for the LoadInfo program.

Example 14-2 shows how to create a workload intelligence job named wijobsales using the LoadInfo program.

Example 14-2 Creating a Workload Intelligence Job

java -classpath $ORACLE_HOME/rdbms/jlib/dbrintelligence.jar:
$ORACLE_HOME/rdbms/jlib/dbrparser.jar:
$ORACLE_HOME/jdbc/lib/ojdbc6.jar:
oracle.dbreplay.workload.intelligence.LoadInfo -job wijobsales -cdir
/test/captures/sales -cstr jdbc:oracle:thin:@myhost:1521:orcl -user workintusr

Generating a Workload Model

To generate a workload model, use the BuildModel program. BuildModel is a Java program that reads data from a captured workload (this data must be generated by the LoadInfo program) and generates a model that describes the workload. This model can then be used to identify frequent template patterns that occur in the workload.

The BuildModel program uses the following syntax:

java oracle.dbreplay.workload.intelligence.BuildModel -cstr connection_string -user username -job job_name

java oracle.dbreplay.workload.intelligence.BuildModel -version

java oracle.dbreplay.workload.intelligence.BuildModel -usage

The BuildModel program supports the following options:

- -cstr
Specifies the JDBC connection string to the database where Workload Intelligence stores the information and intermediate results required for execution (for example, jdbc:oracle:thin@hostname:portnum:ORACLE_SID)

- -user
Specifies the database username. The user must have certain privileges for using Workload Intelligence.

For information about creating a database user with the appropriate privileges, see "Creating a Database User for Workload Intelligence".

- -job
Specifies a name that uniquely identifies the Workload Intelligence job.

- -version
Displays the version information for the BuildModel program.

- -usage
Displays the command-line options for the BuildModel program.

Example 14-3 shows how to generate a workload model using the BuildModel program.

Example 14-3 Generating a Workload Model

java -classpath $ORACLE_HOME/rdbms/jlib/dbrintelligence.jar:
$ORACLE_HOME/rdbms/jlib/dbrparser.jar:
$ORACLE_HOME/jdbc/lib/ojdbc6.jar:
oracle.dbreplay.workload.intelligence.BuildModel -job wijobsales -cstr
jdbc:oracle:thin:@myhost:1521:orcl -user workintusr

Identifying Patterns in a Workload

To identify patterns in a workload, use the FindPatterns program. FindPatterns is a Java program that reads data from a captured workload (this data must be generated by the LoadInfo program) and its corresponding workload model (the workload model must be generated by the BuildModel program), and identifies frequent template patterns that occur in the workload.

The FindPatterns program uses the following syntax:

java oracle.dbreplay.workload.intelligence.FindPatterns -cstr connection_string -user username -job job_name -t threshold

java oracle.dbreplay.workload.intelligence.FindPatterns -version

java oracle.dbreplay.workload.intelligence.FindPatterns -usage

The FindPatterns program supports the following options:

- -cstr
Specifies the JDBC connection string to the database where Workload Intelligence stores the information and intermediate results required for execution (for example, jdbc:oracle:thin@hostname:portnum:ORACLE_SID)

- -user
Specifies the database username. The user must have certain privileges for using Workload Intelligence.

For information about creating a database user with the appropriate privileges, see "Creating a Database User for Workload Intelligence".

- -job
Specifies a name that uniquely identifies the Workload Intelligence job.

- -t
Specifies a threshold probability that defines when a transition from one template to the next is part of the same pattern or the border between two patterns. Valid values include real numbers in the range [0.0, 1.0]. Setting this value is optional; its default value is 0.5.

- -version
Displays the version information for the FindPatterns program.

- -usage
Displays the command-line options for the FindPatterns program.

Example 14-4 shows how to identify frequent template patterns in a workload using the FindPatterns program.

Example 14-4 Identifying Patterns in a Workload

java -classpath $ORACLE_HOME/rdbms/jlib/dbrintelligence.jar:
$ORACLE_HOME/rdbms/jlib/dbrparser.jar:
$ORACLE_HOME/jdbc/lib/ojdbc6.jar:
oracle.dbreplay.workload.intelligence.FindPatterns -job wijobsales -cstr
jdbc:oracle:thin:@myhost:1521:orcl -user workintusr -t 0.2

Generating a Workload Intelligence Report

To generate a Workload Intelligence report, use the GenerateReport program. GenerateReport is a Java program that generates a report to display the results of Workload Intelligence. The Workload Intelligence report is an HTML page that displays the patterns identified in the workload.

The GenerateReport program uses the following syntax:

java oracle.dbreplay.workload.intelligence.GenerateReport -cstr connection_string -user username -job job_name -top top_patterns -out filename

java oracle.dbreplay.workload.intelligence.GenerateReport -version

java oracle.dbreplay.workload.intelligence.GenerateReport -usage

The GenerateReport program supports the following options:

- -cstr
Specifies the JDBC connection string to the database where Workload Intelligence stores the information and intermediate results required for execution (for example, jdbc:oracle:thin@hostname:portnum:ORACLE_SID)

- -user
Specifies the database username. The user must have certain privileges for using Workload Intelligence.

For information about creating a database user with the appropriate privileges, see "Creating a Database User for Workload Intelligence".

- -job
Specifies a name that uniquely identifies the Workload Intelligence job.

- -top
Specifies a number that indicates how many patterns to display in the report. The patterns are ordered by different criteria (number of executions, DB time, and length) and only the defined number of top results are displayed. Setting this value is optional; its default value is 10.

- -out
Specifies the name of the file (in HTML format) where the report is stored. Setting this value is optional; its default value is based on the job name specified in the -job option.

- -version
Displays the version information for the GenerateReport program.

- -usage
Displays the command-line options for the GenerateReport program.

Example 14-5 shows how to generate a Workload Intelligence report using the GenerateReport program.

Example 14-5 Generating a Workload Intelligence Report

java -classpath $ORACLE_HOME/rdbms/jlib/dbrintelligence.jar:
$ORACLE_HOME/rdbms/jlib/dbrparser.jar:
$ORACLE_HOME/jdbc/lib/ojdbc6.jar:
oracle.dbreplay.workload.intelligence.GenerateReport -job wijobsales -cstr
jdbc:oracle:thin:@myhost:1521:orcl -user workintusr -top 5 -out wijobsales.html

Example: Workload Intelligence Results

This section assumes a scenario where Workload Intelligence is used on a captured workload generated by Swingbench, a benchmark used for stress testing Oracle Database.

The most significant pattern discovered by Workload Intelligence consists of the following 6 templates:

SELECT product_id, product_name, product_description, category_id, weight_class,
supplier_id, product_status, list_price, min_price, catalog_url
FROM product_information
WHERE product_id = :1;

SELECT p.product_id, product_name, product_description, category_id, weight_class,
supplier_id, product_status, list_price, min_price, catalog_url,
quantity_on_hand, warehouse_id
FROM product_information p, inventories i
WHERE i.product_id = :1 and i.product_id = p.product_id;

INSERT INTO order_items (order_id, line_item_id, product_id, unit_price, quantity)
VALUES (:1, :2, :3, :4, :5);

UPDATE orders
SET order_mode = :1, order_status = :2, order_total = :3
WHERE order_id = :4;

SELECT /*+ use_nl */ o.order_id, line_item_id, product_id, unit_price, quantity,
order_mode, order_status, order_total, sales_rep_id, promotion_id,
c.customer_id, cust_first_name, cust_last_name, credit_limit, cust_email
FROM orders o, order_items oi, customers c
WHERE o.order_id = oi.order_id
AND o.customer_id = c.customer_id
AND o.order_id = :1;

UPDATE inventories
SET quantity_on_hand = quantity_on_hand - :1
WHERE product_id = :2
AND warehouse_id = :3;

This pattern corresponds to a common user action for ordering a product. In this example, the identified pattern was executed 222,261 times (or approximately 8.21% of the total number of executions) and consumed 58,533.70 seconds of DB time (or approximately 11.21% of total DB time).

Another significant pattern discovered by Workload Intelligence in this example consists of the following 4 templates:

SELECT customer_seq.nextval
FROM dual;

INSERT INTO customers (customer_id, cust_first_name, cust_last_name, nls_language,
nls_territory, credit_limit, cust_email, account_mgr_id)
VALUES (:1, :2, :3, :4, :5, :6, :7, :8);

INSERT INTO logon
VALUES (:1, :2);

SELECT customer_id, cust_first_name, cust_last_name, nls_language, nls_territory,
credit_limit, cust_email, account_mgr_id
FROM customers
WHERE customer_id = :1;

This pattern corresponds to the creation of a new customer account followed by a login in the system. In this example, the identified pattern was executed 90,699 times (or approximately 3.35% of the total number of executions) and consumed 17,484.97 seconds of DB time (or approximately 3.35% of total DB time).

15 Using Consolidated Database Replay

Database Replay enables you to capture a workload on the production system and replay it on a test system. This can be very useful when evaluating or adopting new database technologies because these changes can be tested on a test system without affecting the production system. However, if the new system being tested offers significantly better performance than the existing system, then Database Replay may not accurately predict how much additional workload can be handled by the new system.

For example, if you are consolidating multiple production systems into a single Oracle Exadata Machine, replaying a workload captured from one of the existing systems on Oracle Exadata Machine may result in much lower resource usage (such as host CPU and I/O) during replay because the new system is much more powerful. In this case, it is more useful to assess how the new system will handle the combined workloads from all existing systems, rather than that of a single workload from one system.

Consolidated Database Replay enables you to consolidate multiple workloads captured from one or multiple systems and replay them concurrently on a single test system. In this example, using Consolidated Database Replay will help you to assess how the database consolidation will affect the production system and if a single Oracle Exadata Machine can handle the combined workloads from the consolidated databases.

This chapter describes how to use Consolidated Database Replay and contains the following sections:

- Use Cases for Consolidated Database Replay

- Steps for Using Consolidated Database Replay

- Using Consolidated Database Replay with Enterprise Manager

- Using Consolidated Database Replay with APIs

- About Query-Only Database Replay

- Example: Replaying a Consolidated Workload with APIs

Use Cases for Consolidated Database Replay

Consolidated Database Replay enables you to replay multiple workloads captured from one or multiple systems concurrently. During the replay, every workload capture that is consolidated will start to replay when the consolidated replay begins.

Some typical use cases for Consolidated Database Replay include:

- Database Consolidation Using Pluggable Databases

- Stress Testing

- Scale-Up Testing

Each of these use cases can be performed using the procedures described in this chapter. In addition, you can employ various workload scale-up techniques when using Consolidated Database Replay, as described in Using Workload Scale-Up .

Database Consolidation Using Pluggable Databases

One use for Consolidated Database Replay is to assess if the system can handle the combined workload from a database consolidation. For example, assume that you want to consolidate the databases for the CRM, ERP, and SCM applications by migrating them to pluggable databases (PDBs). You can use Consolidated Database Replay to combine the captured workloads from the three applications and replay them concurrently on PDBs. For an example of this use case, see "Example: Replaying a Consolidated Workload with APIs".

Stress Testing

Another use for Consolidated Database Replay is for stress testing or capacity planning. For example, assume that you are expecting the workload for the Sales application to double during the holiday season. You can use Consolidated Database Replay to test the added stress on the system by doubling the workload and replaying the combined workload. For an example of this use case, see "Using Time Shifting".

Scale-Up Testing

A third use for Consolidated Database Replay is for scale-up testing. For example, assume that you want to test if your system can handle captured workloads from the Financials application and the Orders application concurrently. You can use Consolidated Database Replay to test the effects of the scaled-up workload on your system by combining the workloads and replaying them simultaneously. For examples of this use case, see "Using Workload Folding" and "Using Schema Remapping".

Steps for Using Consolidated Database Replay

This section describes the steps involved when using Consolidated Workload Replay and contains the following topics:

- Capturing Database Workloads for Consolidated Database Replay

- Setting Up the Test System for Consolidated Database Replay

- Preprocessing Database Workloads for Consolidated Database Replay

- Replaying Database Workloads for Consolidated Database Replay

- Reporting and Analysis for Consolidated Database Replay

Capturing Database Workloads for Consolidated Database Replay

Consolidated Database Replay does not require any special steps for capturing database workloads. The steps for capturing database workloads are exactly the same as for capturing a single workload for Database Replay, as described in Capturing a Database Workload .

This section contains the following topics for workload captures that are specific to Consolidated Database Replay:

- Supported Types of Workload Captures

- Capture Subsets

Supported Types of Workload Captures

Consolidated Database Replay supports multiple workloads captured from one or multiple systems running Oracle Database 9i Release 2 (release 9.2.0.8.0) or higher on one or multiple operating systems. For example, you can use workloads captured from one system running Oracle Database 9i Release 2 (release 9.2.0.8.0) on HP-UX and another system running Oracle Database 10g Release 2 (release 10.2.0.4.0) on AIX.

Note:

Consolidated Database Replay is only available on Oracle Database 11g Release 2 (release 11.2.0.2.0) and higher.

Capture Subsets

Consolidated Database Replay enables you to transform existing workload captures into new, smaller pieces of capture subsets. You can then generate new workload captures from the capture subsets that can be used in different use cases, as described in "Use Cases for Consolidated Database Replay".

A capture subset is a piece of a workload capture that is defined from an existing workload capture by applying a time range. The time range is specified as an offset from the start of the workload capture. All user workloads captured within the specified time range are included in the defined capture subset.

For example, assume that a workload was captured from 2 a.m. to 8 p.m. and the peak workload is identified to be from 10 a.m. to 4 p.m. You can define a capture subset to represent the peak workload by applying a time range that starts at 8 hours after the start of the workload (or 10 a.m.) and ends at 14 hours after the start of the workload (or 4 p.m.).

However, if a capture subset only contains recorded user workloads that satisfy the specified time range, user logins that occurred before the specified time range are not recorded. If these user logins are required for replay, then the capture subset may not be replayable. For example, if a user session starts at 9:30 a.m. and ends at 10:30 a.m. and the specified time range for the capture subset is 10:00 a.m. to 4:00 p.m., the replay may fail if the user login at 9:30 a.m. is not included in the workload. Similarly, the specified time range may also include incomplete user calls that are only partially recorded if a user sessions starts at 3:30 p.m. but does not complete until 4:30 p.m.

Consolidated Database Replay addresses this problem by including only incomplete user calls caused by the start time of the specified time range. To avoid including the same incomplete user calls twice if the workload capture is folded, incomplete user calls caused by the end time are not included by default. Therefore, a capture subset is essentially the minimal number of recorded user calls during a specified time range that are required for proper replay, including the necessary user logins, alter session statements, and incomplete user calls caused by the start time.

See Also:

"Generating Capture Subsets Using APIs"

Setting Up the Test System for Consolidated Database Replay

Setting up the test system for Consolidated Database Replay is similar to setting up a test system for Database Replay, as described in "Steps for Replaying a Database Workload". However, there are some additional considerations when setting up a replay database for Consolidated Database Replay.

To minimize divergence during the replay, the test system should contain the same application data and the state of the application data should be logically equivalent to that of the capture system at the start time of each workload capture. However, because a consolidated capture may contain multiple workload captures from different production systems, the test system needs to be set up for all the captures. In this case, it is recommended that the multitenant architecture be used to consolidate multiple databases, so that each database will have equivalent data to its capture system at the capture start time.

For Consolidated Database Replay, all participating workload captures must be placed under a new capture directory on the test system. You can copy all the workload captures into the new capture directory, or create symbolic links pointing to the original workload captures. Before consolidating the workload captures, ensure that the new capture directory has enough disk space to store all participating captures.

Figure 15-1 illustrates how to set up the test system and new capture directory to consolidate three workload captures.

Figure 15-1 Setting Up the Test System for Consolidated Database Replay

See Also:

- "Setting the Consolidated Replay Directory Using APIs"

- Oracle Database Concepts for information about the multitenant architecture

Preprocessing Database Workloads for Consolidated Database Replay

Preprocessing a database workload for Consolidated Database Replay is similar to preprocessing a database workload for Database Replay, as described in Preprocessing a Database Workload .

For Consolidated Database Replay, preprocess each captured workload into its own directory. Do not combine different workload captures into one directory for preprocessing. Preprocessing of captured workloads must be performed using a database running the same version of Oracle Database as that of the test system where the workloads will be replayed.

Replaying Database Workloads for Consolidated Database Replay

Replaying consolidated workloads using Consolidated Database Replay is quite different from replaying a single database workload using Database Replay.

This section contains the following topics for replaying workloads that are specific to Consolidated Database Replay:

- Defining Replay Schedules

- Remapping Connections for Consolidated Database Replay

- Remapping Users for Consolidated Database Replay

- Preparing for Consolidated Database Replay

- Replaying Individual Workloads

Defining Replay Schedules

A replay schedule adds one or multiple workload captures to a consolidated replay and specifies the order in which the captures will start during replay. A replay schedule must be created before a consolidated replay can be initialized. Multiple replay schedules can be defined for a consolidated replay. During replay initialization, you can select from any of the existing replay schedules.

Replay schedules perform two types of operation:

- Adding Workload Captures

- Adding Schedule Orders

See Also:

"Defining Replay Schedules Using APIs"

Adding Workload Captures

The first type of operation performed by a replay schedule is to add the participating workload captures to a replay.

When a workload capture is added to a replay schedule, a unique number is returned to identify the workload capture. A workload capture can be added to a replay schedule more than once, as it will be assigned a different capture number each time it is added. The replay schedule will point to the same capture directory each time to avoid a waste of disk space by copying the capture each time it is added.

See Also:

"Adding Workload Captures to Replay Schedules Using APIs"

Adding Schedule Orders

The second type of operation performed by a replay schedule is to add schedule orders that specify the order in which the participating workload captures will start during replay.

A schedule order defines an order between the start of two workload captures that have been added to the replay schedule. Multiple schedule orders can be added to a replay schedule. For example, assume that a replay schedule has three workload captures added. One schedule order can be added to specify that Capture 2 must wait for Capture 1 to complete before starting. Another schedule order can be added to specify that Capture 3 must wait for Capture 1 to complete before starting. In this case, both Capture 2 and Capture 3 must wait for Capture 1 to complete before starting.

It is possible for a replay schedule to not contain any schedule orders. In this case, all participating workload captures in the replay schedule will start to replay simultaneously when the consolidated replay begins.

See Also:

"Adding Schedule Orders to Replay Schedules Using APIs"

Remapping Connections for Consolidated Database Replay

As in the case with replaying a single database workload using Database Replay, captured connection strings used to connect to the production system need to be remapped to the replay system, as described in "Connection Remapping".

For Consolidated Database Replay, you need to remap captured connection strings from multiple workload captures to different connection strings during replay.

See Also:

"Remapping Connection Using APIs"

Remapping Users for Consolidated Database Replay

As in the case with replaying a single database workload using Database Replay, usernames of database users and schemas used to connect to the production system can be remapped during replay, as described in "User Remapping".

For Consolidated Database Replay, you can choose to remap the captured users from multiple workload captures to different users or schemas during replay.

See Also:

"Remapping Users Using APIs"

Preparing for Consolidated Database Replay

As is the case with replaying a single database workload using Database Replay, replay options are defined during preparation of a replay, as described in "Specifying Replay Options".

For Consolidated Database Replay, all participating workload captures in a consolidated replay use the same replay options during replay that are defined during replay preparation.

See Also:

"Preparing for Consolidated Database Replay Using APIs"

Replaying Individual Workloads

It is recommended that each of the participating workloads be replayed individually before replaying the consolidated workload, as described in Replaying a Database Workload .

The individual replays can establish a baseline performance for each workload capture and be used to analyze the performance of the consolidated replay.

Reporting and Analysis for Consolidated Database Replay

Reporting and analysis for Consolidated Database Replay is performed using the replay compare period report, as described in "Using Replay Compare Period Reports".

The replay compare period report for Consolidated Database Replay identifies the Active Session History (ASH) data for each individual workload capture and compares the ASH data from the workload capture to the filtered ASH data from the consolidated replay. Use this report to compare replays of the same consolidated workload capture.

The replay compare period report for Consolidated Database Replay treats the consolidated replay as multiple Capture vs. Replay comparisons. The summary section of the report contains a table that summarizes all individual Capture vs. Replay comparisons. Review the information in this section to gain a general understanding of how the consolidated replay ran.

Figure 15-2 shows the summary section of a sample replay compare period report for Consolidated Database Replay.

Figure 15-2 Compare Period Report: Consolidated Replay

The rest of the sections in the report resemble the ASH Data Comparison section of the replay compare period report and are formed by joining all Capture vs. Replay reports in the consolidated replay. For a description of this section, see "ASH Data Comparison".

Using Consolidated Database Replay with Enterprise Manager

This section describes how to use Consolidated Database Replay with Enterprise Manager.

The primary tool for replaying consolidated database workloads is Oracle Enterprise Manager. If Oracle Enterprise Manager is unavailable, you can also replay consolidated database workloads using APIs, as described in "Using Consolidated Database Replay with APIs".

The process for replaying a consolidated database workload is nearly identical to that of replaying a single database workload. The differences are documented in the procedures for single replays in the following sections:

- "Creating a Database Replay Task" in Preprocessing a Database Workload

- "Preprocessing the Workload and Deploying the Replay Clients" in Preprocessing a Database Workload

- "Replaying a Database Workload Using Enterprise Manager" in Replaying a Database Workload

The following list provides a summary of the differences between replaying a consolidated database workload versus replaying a single database workload:

- When creating a replay task, you need to select two or more captured workloads from the Select Captures table in the Create Task page.

- The Preprocess Captured Workload: Copy Workload step of the wizard has more than one choice for the Capture Name drop-down, so you may need to enter multiple credentials for the current location of the workload directory.

- The Preprocess Captured Workload: Select Directory step of the wizard does not display a Capture Summary as it does for single replays.

- The Replay Workload: Copy Workload step of the wizard has more than one choice for the Capture Name drop-down, so you may need to enter multiple credentials for the current location of the workload directory.

- The Replay Workload: Select Directory step of the wizard does not display a Capture Summary as it does for single replays.

- The Replay Workload: Initialize Options step of the wizard does not display the Identify Source section.

- The Replay Workload: Customize Options step of the wizard has more than one choice for the Capture Name drop-down in the Connection Mappings tab, so you can remap connections for each captured workload. The option to use a single connect descriptor or net service name is not available.

Using Consolidated Database Replay with APIs

This section describes how to create and replay consolidated workloads using the DBMS_WORKLOAD_REPLAY package. You can also create and replay consolidated workloads using Oracle Enterprise Manager, as described in "Using Consolidated Database Replay with Enterprise Manager".

Creating and replay a consolidated workload using APIs is a multi-step process that involves:

- Generating Capture Subsets Using APIs

- Setting the Consolidated Replay Directory Using APIs

- Defining Replay Schedules Using APIs

- Running Consolidated Database Replay Using APIs

See Also:

Oracle Database PL/SQL Packages and Types Reference for information about the DBMS_WORKLOAD_REPLAY package

Generating Capture Subsets Using APIs

This section describes how to generate capture subsets from existing workload captures using the DBMS_WORKLOAD_REPLAY package. For information about capture subsets, see "Capture Subsets".

To generate a capture subset from existing workload captures:

1. Use the GENERATE_CAPTURE_SUBSET procedure:

DBMS_WORKLOAD_REPLAY.GENERATE_CAPTURE_SUBSET (
input_capture_dir        IN VARCHAR2,
output_capture_dir       IN VARCHAR2,
new_capture_name         IN VARCHAR2,
begin_time               IN NUMBER,
begin_include_incomplete IN BOOLEAN   DEFAULT TRUE,
end_time                 IN NUMBER,
end_include_incomplete   IN BOOLEAN   DEFAULT FALSE,
parallel_level           IN NUMBER    DEFAULT NULL);

2. Set the input_capture_dir parameter to the name of the directory object that points to an existing workload capture.

3. Set the output_capture_dir parameter to the name of the directory object that points to an empty directory where the new workload capture will be stored.

4. Set the new_capture_name parameter to the name of the new workload capture that is to be generated.

5. Set the other parameters, which are optional, as appropriate.
For information about these parameters, see Oracle Database PL/SQL Packages and Types Reference.

This example shows how to create a capture subset named peak_wkld at directory object peak_capdir from an existing workload capture at directory object rec_dir. The capture subset includes workload from 2 hours after the start of the workload capture (or 7,200 seconds) to 3 hours after the start of the workload capture (or 10,800 seconds).

EXEC DBMS_WORKLOAD_REPLAY.GENERATE_CAPTURE_SUBSET ('rec_dir', 'peak_capdir',
'peak_wkld', 7200, TRUE, 10800, FALSE, 1);

See Also:

Oracle Database PL/SQL Packages and Types Reference for information about the GENERATE_CAPTURE_SUBSET procedure

Setting the Consolidated Replay Directory Using APIs

This section describes how to set the consolidated replay directory on the test system using the DBMS_WORKLOAD_REPLAY package. Set the consolidated replay directory to a directory on the test system that contains the workload captures to be consolidated and replayed. For information about setting up the test system, see "Setting Up the Test System for Consolidated Database Replay".

To set the replay directory:

1. Use the SET_CONSOLIDATED_DIRECTORY procedure:

DBMS_WORKLOAD_REPLAY.SET_CONSOLIDATED_DIRECTORY (
replay_dir IN VARCHAR2);

2. Set the replay_dir parameter to the name of the directory object that points to the operating system directory containing the workload captures to be used for workload consolidation.

Tip:

The SET_REPLAY_DIRECTORY procedure is deprecated and replaced by the SET_CONSOLIDATED_DIRECTORY procedure.

This example shows how to set the replay directory to a directory object named rep_dir.

EXEC DBMS_WORKLOAD_REPLAY.SET_CONSOLIDATED_DIRECTORY ('rep_dir');

You can also use the DBMS_WORKLOAD_REPLAY package to view the current consolidated replay directory that has been set by the SET_CONSOLIDATED_DIRECTORY procedure.

To view the current consolidated replay directory that has been set:

- Use the GET_REPLAY_DIRECTORY function:

DBMS_WORKLOAD_REPLAY.GET_REPLAY_DIRECTORY RETURN VARCHAR2;

If no consolidated replay directory has been set, then the function returns NULL.

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the SET_REPLAY_DIRECTORY procedure

- Oracle Database PL/SQL Packages and Types Reference for information about the GET_REPLAY_DIRECTORY function

Defining Replay Schedules Using APIs

This section describes how to define replay schedules using the DBMS_WORKLOAD_REPLAY package. For information about replay schedules, see "Defining Replay Schedules".

Before defining replay schedules, ensure that the following prerequisites are met:

- All workload captures are preprocessed using the PROCESS_CAPTURE procedure on a system running the same database version as the replay system, as described in Preprocessing a Database Workload .

- All capture directories are copied to the replay directory on the replay system

- Replay directory is set using the SET_REPLAY_DIRECTORY procedure, as described in "Setting the Consolidated Replay Directory Using APIs".

- Database state is not in replay mode

To define replay schedules:

1. Create a new replay schedule, as described in "Creating Replay Schedules Using APIs".

2. Add workload captures to the replay schedule, as described in "Adding Workload Captures to Replay Schedules Using APIs".

3. Add schedule orders to the replay schedule, as described in "Adding Schedule Orders to Replay Schedules Using APIs".

4. Save the replay schedule, as described in "Saving Replay Schedules Using APIs".

Creating Replay Schedules Using APIs

This section describes how to create replay schedules using the DBMS_WORKLOAD_REPLAY package. For information about replay schedules, see "Defining Replay Schedules".

To create a replay schedule:

1. Use the BEGIN_REPLAY_SCHEDULE procedure:

DBMS_WORKLOAD_REPLAY.BEGIN_REPLAY_SCHEDULE (
schedule_name  IN VARCHAR2);

2. Set the schedule_name parameter to the name of this replay schedule.

Note:

The BEGIN_REPLAY_SCHEDULE procedure initiates the creation of a reusable replay schedule. Only one replay schedule can be defined at a time. Calling this procedure again while a replay schedule is being defined will result in an error.

This example shows how to create a replay schedule named peak_schedule.

EXEC DBMS_WORKLOAD_REPLAY.BEGIN_REPLAY_SCHEDULE ('peak_schedule');

See Also:

Oracle Database PL/SQL Packages and Types Reference for information about the BEGIN_REPLAY_SCHEDULE procedure

Adding Workload Captures to Replay Schedules Using APIs

This section describes how to add workload captures to and remove workload captures from replay schedules using the DBMS_WORKLOAD_REPLAY package. For information about adding workload captures to replay schedules, see "Adding Workload Captures".

Before adding workload captures to a replay schedule, ensure that the following prerequisite is met:

- A replay schedule to which the workload captures are to be added is created.
For information about creating a replay schedule, see "Creating Replay Schedules Using APIs".

To add workload captures to a replay schedule:

1. Use the ADD_CAPTURE function:

DBMS_WORKLOAD_REPLAY.ADD_CAPTURE (
capture_dir_name    IN VARCHAR2,
start_delay_seconds IN NUMBER  DEFAULT 0,
stop_replay         IN BOOLEAN DEFAULT FALSE,
take_begin_snapshot IN BOOLEAN DEFAULT FALSE,
take_end_snapshot   IN BOOLEAN DEFAULT FALSE,
query_only          IN BOOLEAN DEFAULT FALSE)
RETURN NUMBER;

DBMS_WORKLOAD_REPLAY.ADD_CAPTURE (
capture_dir_name    IN VARCHAR2,
start_delay_seconds IN NUMBER,
stop_replay         IN VARCHAR2,
take_begin_snapshot IN VARCHAR2 DEFAULT 'N',
take_end_snapshot   IN VARCHAR2 DEFAULT 'N',
query_only          IN VARCHAR2 DEFAULT 'N')
RETURN NUMBER;

This function returns an unique identifier that identifies the workload capture in this replay schedule.

See:

"About Query-Only Database Replay" for information about query-only database replays.

Note:

Query-only database replays are meant to be used and executed in test environments only.

- Do not use query-only database replays on production systems.

- Divergence is expected during query-only database replays.

2. Set the capture_dir_name parameter to the name of the directory object that points to the workload capture under the top-level replay directory.
The directory must contain a valid workload capture that is preprocessed on a system running the same database version as the replay system.

3. Set the other parameters, which are optional, as appropriate.
For information about these parameters, see Oracle Database PL/SQL Packages and Types Reference.

The following example shows how to add a workload capture named peak_wkld to a replay schedule by using the ADD_CAPTURE function in a SELECT statement.

SELECT DBMS_WORKLOAD_REPLAY.ADD_CAPTURE ('peak_wkld')
FROM dual;

You can also use the DBMS_WORKLOAD_REPLAY package to remove workload captures from a replay schedule.

To remove workload captures from a replay schedule:

1. Use the REMOVE_CAPTURE procedure:

DBMS_WORKLOAD_REPLAY.REMOVE_CAPTURE (
schedule_capture_number IN NUMBER);

2. Set the schedule_capture_number parameter to the unique identifier that identifies the workload capture in this replay schedule.
The unique identifier is the same identifier that was returned by the ADD_CAPTURE function when the workload capture was added to the replay schedule.

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the ADD_CAPTURE function

- Oracle Database PL/SQL Packages and Types Reference for information about the REMOVE_CAPTURE procedure

Adding Schedule Orders to Replay Schedules Using APIs

This section describes how to add schedule orders to and remove schedule orders from replay schedules using the DBMS_WORKLOAD_REPLAY package. For information about adding schedule orders to replay schedules, see "Adding Schedule Orders".

Before adding schedule orders to a replay schedule, ensure that the following prerequisites are met:

- A replay schedule to which the schedule orders are to be added is created.
For information about creating a replay schedule, see "Creating Replay Schedules Using APIs".

- All workload captures participating in the schedule order are added to the replay schedule.
For information about adding workload captures to a replay schedule, see "Adding Workload Captures to Replay Schedules Using APIs".

Note:

Adding schedule orders to a replay schedule is optional. If you do not add a schedule order to a replay schedule, then all workload captures added to the replay schedule will start to replay simultaneously when the consolidated replay begins.

To add schedule orders to a replay schedule:

1. Use the ADD_SCHEDULE_ORDERING function:

DBMS_WORKLOAD_REPLAY.ADD_SCHEDULE_ORDERING (
schedule_capture_id IN VARCHAR2,
wait_for_capture_id IN VARCHAR2)
RETURN NUMBER;

This function adds a schedule order between two workload captures that have been added to the replay schedule. If a schedule order cannot be added, it returns a non-zero error code.

2. Set the schedule_capture_id parameter to the workload capture that you want to wait in this schedule order.

3. Set the wait_for_capture_id parameter to the workload capture that you want to be completed before the other workload capture can start in this schedule order.

You can also use the DBMS_WORKLOAD_REPLAY package to remove schedule orders from a replay schedule.

To remove schedule orders from a replay schedule:

1. Use the REMOVE_SCHEDULE_ORDERING procedure:

DBMS_WORKLOAD_REPLAY.REMOVE_SCHEDULE ORDERING (
schedule_capture_id IN VARCHAR2,
wait_for_capture_id IN VARCHAR2);

2. Set the schedule_capture_id parameter to the workload capture waiting in this schedule order.

3. Set the wait_for_capture_id parameter to the workload capture that needs to be completed before the other workload capture can start in this schedule order.

To view schedule orders:

- Use the DBA_WORKLOAD_SCHEDULE_ORDERING view.

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the ADD_SCHEDULE_ORDERING function

- Oracle Database PL/SQL Packages and Types Reference for information about the REMOVE_SCHEDULE_ORDERING procedure

- Oracle Database Reference for information about the DBA_WORKLOAD_SCHEDULE_ORDERING view

Saving Replay Schedules Using APIs

This section describes how to save replay schedules that been defined using the DBMS_WORKLOAD_REPLAY package.

Before saving a replay schedule, ensure that the following prerequisites are met:

- A replay schedule that will be saved is created.
For information about creating a replay schedule, see "Creating Replay Schedules Using APIs".

- All workload captures participating in the schedule order are added to the replay schedule.
For information about adding workload captures to a replay schedule, see "Adding Workload Captures to Replay Schedules Using APIs".

- Any schedule orders that you want to use are added to the replay schedule (this step is optional).
For information about adding schedule orders to a replay schedule, see "Adding Schedule Orders to Replay Schedules Using APIs".

To save a replay schedule:

- Use the END_REPLAY_SCHEDULE procedure:

DBMS_WORKLOAD_REPLAY.END_REPLAY_SCHEDULE;

This procedure completes the creation of a replay schedule. The replay schedule is saved and associated with the replay directory. Once a replay schedule is saved, you can use it for a consolidated replay.

To view replay schedules:

- Use the DBA_WORKLOAD_REPLAY_SCHEDULES view.

See Also:

- Oracle Database PL/SQL Packages and Types Reference for information about the END_REPLAY_SCHEDULE procedure

- Oracle Database Reference for information about the DBA_WORKLOAD_REPLAY_SCHEDULES view

Running Consolidated Database Replay Using APIs

This section describes how to run Consolidated Database Replay using the DBMS_WORKLOAD_REPLAY package. For information about consolidated replay, see "Replaying Database Workloads for Consolidated Database Replay".

Before running Consolidated Database Replay, ensure that the following prerequisites are met:

- All workload captures are preprocessed using the PROCESS_CAPTURE procedure on a system running the same database version as the replay system, as described in Preprocessing a Database Workload .

- All capture directories are copied to the replay directory on the replay system

- Replay directory is set using the SET_REPLAY_DIRECTORY procedure, as described in "Setting the Consolidated Replay Directory Using APIs".

- Database is logically restored to the same application state as that of all the capture systems at the start time of all workload captures.

To run Consolidated Database Replay:

1. Initialize the replay data, as described in "Initializing Consolidated Database Replay Using APIs".

2. Remap connections strings, as described in "Remapping Connection Using APIs".

3. Remap users, as described in "Remapping Users Using APIs".
Remapping users is optional.

4. Prepare the consolidated replay, as described in "Preparing for Consolidated Database Replay Using APIs".

5. Set up and start the replay clients, as described in "Setting Up Replay Clients".

6. Start the consolidated replay, as described in "Starting Consolidated Database Replay Using APIs".

7. Generate reports and perform analysis, as described in "Reporting and Analysis for Consolidated Database Replay".

Initializing Consolidated Database Replay Using APIs

This section describes how to initialize the replay data for a consolidated replay using the DBMS_WORKLOAD_REPLAY package.

Initializing the replay data performs the following operations:

- Puts the database state in initialized mode for the replay of a consolidated workload.

- Points to the replay directory that contains all workload captures participating in the replay schedule.

- Loads the necessary metadata into tables required for replay.
For example, captured connection strings are loaded into a table where they can be remapped for replay.

To initialize Consolidated Database Replay:

1. Use the INITIALIZED_CONSOLIDATED_REPLAY procedure:

DBMS_WORKLOAD_REPLAY.INITIALIZE_CONSOLIDATED_REPLAY (
replay_name    IN VARCHAR2,
schedule_name  IN VARCHAR2);

2. Set the replay_name parameter to the name of the consolidated replay.

3. Set the schedule_name parameter to the name of the replay schedule to use.
The schedule_name parameter is the name of the replay schedule used during its creation, as described in "Creating Replay Schedules Using APIs".

The following example shows how to initialize a consolidated replay named peak_replay using the replay schedule named peak_schedule.

EXEC DBMS_WORKLOAD_REPLAY.INITIALIZE_CONSOLIDATED_REPLAY ('peak_replay',
'peak_schedule');

See Also:

Oracle Database PL/SQL Packages and Types Reference for information about the INITIALIZE_CONSOLIDATED_REPLAY procedure

Remapping Connection Using APIs

This section describes how to remap connection strings for a consolidated replay using the DBMS_WORKLOAD_REPLAY package. For information about connection remapping, see "Remapping Connections for Consolidated Database Replay".

To remap connection strings:

1. Use the REMAP_CONNECTION procedure:

DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (
schedule_cap_id   IN NUMBER,
connection_id     IN NUMBER,
replay_connection IN VARCHAR2);

This procedure remaps the captured connection to a new connection string for all participating workload captures in the replay schedule.

2. Set the schedule_capture_id parameter to a participating workload capture in the current replay schedule.
The schedule_capture_id parameter is the unique identifier returned when adding the workload capture to the replay schedule, as described in "Adding Workload Captures to Replay Schedules Using APIs".

3. Set the connection_id parameter to the connection to be remapped.
The connection_id parameter is generated when replay data is initialized and corresponds to a connection from the workload capture.

4. Set the replay_connection parameter to the new connection string that will be used during replay.

See Also:

Oracle Database PL/SQL Packages and Types Reference for information about the REMAP_CONNECTION procedure

Remapping Users Using APIs

This section describes how to remap users for a consolidated replay using the DBMS_WORKLOAD_REPLAY package. For information about remapping users, see "Remapping Users for Consolidated Database Replay".

Before remapping users, ensure that the following prerequisites are met:

- Replay data is initialized, as described in "Initializing Consolidated Database Replay Using APIs".

- The database state is not in replay mode.

To remap users:

1. Use the SET_USER_MAPPING procedure:

DBMS_WORKLOAD_REPLAY.SET_USER_MAPPING (
schedule_cap_id IN NUMBER,
capture_user    IN VARCHAR2,
replay_user     IN VARCHAR2);

2. Set the schedule_capture_id parameter to a participating workload capture in the current replay schedule.
The schedule_capture_id parameter is the unique identifier returned when adding the workload capture to the replay schedule, as described in "Adding Workload Captures to Replay Schedules Using APIs".

3. Set the capture_user parameter to the username of the user or schema captured during the time of the workload capture.

4. Set the replay_user parameter to the username of a new user or schema to which the captured user is remapped during replay.
If this parameter is set to NULL, then the mapping is disabled.

This example shows how to remap the PROD user used during capture to the TEST user during replay for the workload capture identified as 1001.

EXEC DBMS_WORKLOAD_REPLAY.SET_USER_MAPPING (1001, 'PROD', 'TEST');

See Also:

Oracle Database PL/SQL Packages and Types Reference for information about the SET_USER_MAPPING procedure

Preparing for Consolidated Database Replay Using APIs

This section describes how to prepare a consolidated replay using the DBMS_WORKLOAD_REPLAY package. For information about preparing consolidated replays, see "Preparing for Consolidated Database Replay".

Before preparing a consolidated replay, ensure that the following prerequisites are met:

- Replay data is initialized, as described in "Initializing Consolidated Database Replay Using APIs".

- Captured connections are remapped, as described in "Remapping Connection Using APIs".

- Users are mapped, as described in "Remapping Users Using APIs".
Remapping users is optional. However, if you are planning to remap users during replay, then it must be completed before preparing the consolidated replay.

Preparing a consolidated replay performs the following operations:

- Specifies the replay options, such as synchronization mode (or COMMIT order), session connection rate, and session request rate.

- Puts the database state in replay mode.

- Enables the start of replay clients.

Note:

Consolidated Database Replay only supports unsynchronized mode and OBJECT_ID-based synchronization. SCN-based synchronization is currently not supported.

To prepare a consolidated replay:

- Use the PREPARE_CONSOLIDATED_REPLAY procedure:

DBMS_WORKLOAD_REPLAY.PREPARE_CONSOLIDATED_REPLAY (
synchronization         IN VARCHAR2 DEFAULT 'OBJECT_ID',
connect_time_scale      IN NUMBER   DEFAULT 100,
think_time_scale        IN NUMBER   DEFAULT 100,
think_time_auto_correct IN BOOLEAN  DEFAULT TRUE,
capture_sts             IN BOOLEAN  DEFAULT FALSE,
sts_cap_interval        IN NUMBER   DEFAULT 300);

For information about these parameters and how to set them, see "Specifying Replay Options".

Note:

Be sure to set synchronization to false when you use the PREPARE_CONSOLIDATED_REPLAY procedure.

See Also:

Oracle Database PL/SQL Packages and Types Reference for information about the PREPARE_CONSOLIDATED_REPLAY procedure

Starting Consolidated Database Replay Using APIs

This section describes how to start a consolidated replay using the DBMS_WORKLOAD_REPLAY package.

Before starting a consolidated replay, ensure that the following prerequisites are met:

- The consolidated replay is prepared, as described in "Preparing for Consolidated Database Replay Using APIs".

- An adequate number of replay clients are started.
For information about setting up and starting replay clients, see "Setting Up Replay Clients".

To start a consolidated replay:

- Use the START_CONSOLIDATED_REPLAY procedure:

DBMS_WORKLOAD_REPLAY.START_CONSOLIDATED_REPLAY;

See Also:

Oracle Database PL/SQL Packages and Types Reference for information about the START_CONSOLIDATED_REPLAY procedure

About Query-Only Database Replay

In a query-only database replay, only the read-only queries of a workload capture are replayed. In other words, in a query-only replay, only SELECT statements are sent to the server at replay time. No DML statements are executed during a query-only replay, and the replay does not make any changes to user schemas or data.

Note:

A query-only database replay can be performed with Consolidated Database Replay only.

Note:

Query-only database replays are meant to be used and executed in test environments only.

- Do not use query-only database replays on production systems.

- Divergence is expected during query-only database replays.

Use Cases for Query-Only Database Replay

The use cases for query-only database replay are:

- To warm up the database buffer cache
In some cases, a workload is captured when the database buffer cache is warm (data blocks are already in the buffer cache). However, when you replay that workload on the test system, the buffer cache will not be warm, and the data blocks will need to be loaded from disk initially. This may make the replay duration longer than the capture duration, and increase the database time.

To avoid having to warm up the buffer cache, you can perform a query-only replay and then perform the read/write replay without restarting the database and without flushing the buffer cache. Note that you do not have to restart the database after a query-only replay because a query-only replay is read-only.

- To find regressions
A query-only replay is a good and easy way to find regressions from the read-only part of the workload with concurrency. The read-only part includes SELECT (not SELECT...FOR UPDATE) statements, PL/SQL without DMLs and DDLs, LOB reads, and so on. It is typically the main part of the workload capture.

Performing a Query-Only Database Replay

To perform a query-only database replay, follow the instructions in "Using Consolidated Database Replay with APIs". When you use the ADD_CAPTURE function to add workload captures to the replay schedule as described in "Adding Workload Captures to Replay Schedules Using APIs", set the query_only parameter to Y.

Example: Replaying a Consolidated Workload with APIs

This section assumes a scenario where workloads from three separate production systems running different versions of Oracle Database on various operating systems are being consolidated.

This scenario uses the following assumptions:

- The first workload to be consolidated is captured from the CRM system, which is running Oracle Database 10g Release 2 (release 10.2.0.4) on a Solaris server.

- The second workload to be consolidated is captured from the ERP system, which is running Oracle Database 10g Release 2 (release 10.2.0.5) on a Linux server.

- The third workload to be consolidated is captured from the SCM system, which is running Oracle Database 11g Release 2 (release 11.2.0.2) on a Solaris server.

- The test system is set up as a multitenant container database (CDB) running Oracle Database 12c Release 1 (release 12.1.0.1).

- The CDB contains three PDBs created from the CRM, ERP, and SCM systems.

- Each PDB contained within the CDB is restored to the same application data state as the CRM, ERP, and SCM systems at the capture start time.

Figure 15-3 illustrates this scenario.

Figure 15-3 Scenario for Consolidating Three Workloads

To consolidate the workloads and replay the consolidated workload in this scenario:

1. On the test system, preprocess the individual workload captures into separate directories:

- For the CRM workload:

a. Create a directory object:

CREATE OR REPLACE DIRECTORY crm AS '/u01/test/cap_crm';

b. Ensure that the captured workload from the CRM system is stored in this directory.

c. Preprocess the workload:

EXEC DBMS_WORKLOAD_REPLAY.PROCESS_CAPTURE ('CRM');

- For the ERP workload:

a. Create a directory object:

CREATE OR REPLACE DIRECTORY erp AS '/u01/test/cap_erp';

b. Ensure that the captured workload from the ERP system is stored in this directory.

c. Preprocess the workload:

EXEC DBMS_WORKLOAD_REPLAY.PROCESS_CAPTURE ('ERP');

- For the SCM workload:

a. Create a directory object:

CREATE OR REPLACE DIRECTORY scm AS '/u01/test/cap_scm';

b. Ensure that the captured workload from the SCM system is stored in this directory.

c. Preprocess the workload:

EXEC DBMS_WORKLOAD_REPLAY.PROCESS_CAPTURE ('SCM');

2. Create a root directory to store the preprocessed workloads:

mkdir '/u01/test/cons_dir';
CREATE OR REPLACE DIRECTORY cons_workload AS '/u01/test/cons_dir';

3. Copy each preprocessed workload directory into the root directory:

cp -r /u01/test/cap_crm /u01/test/cons_dir
cp -r /u01/test/cap_erp /u01/test/cons_dir
cp -r /u01/test/cap_scm /u01/test/cons_dir

4. For each workload, create a directory object using the new operating system directory path:

CREATE OR REPLACE DIRECTORY crm AS '/u01/test/cons_dir/cap_crm';
CREATE OR REPLACE DIRECTORY erp AS '/u01/test/cons_dir/cap_erp';
CREATE OR REPLACE DIRECTORY scm AS '/u01/test/cons_dir/cap_scm';

5. Set the replay directory to the root directory previously created in Step 2:

EXEC DBMS_WORKLOAD_REPLAY.SET_REPLAY_DIRECTORY ('CONS_WORKLOAD');

6. Create a replay schedule and add the workload captures:

EXEC DBMS_WORKLOAD_REPLAY.BEGIN_REPLAY_SCHEDULE ('CONS_SCHEDULE');
SELECT DBMS_WORKLOAD_REPLAY.ADD_CAPTURE ('CRM') FROM dual;
SELECT DBMS_WORKLOAD_REPLAY.ADD_CAPTURE ('ERP') FROM dual;
SELECT DBMS_WORKLOAD_REPLAY.ADD_CAPTURE ('SCM') FROM dual;
EXEC DBMS_WORKLOAD_REPLAY.END_REPLAY_SCHEDULE;

7. Initialize the consolidated replay:

EXEC DBMS_WORKLOAD_REPLAY.INITIALIZE_CONSOLIDATED_REPLAY ('CONS_REPLAY',
'CONS_SCHEDULE');

8. Remap connections:

a. Query the DBA_WORKLOAD_CONNECTION_MAP view for the connection mapping information:

SELECT schedule_cap_id, conn_id, capture_conn, replay_conn
FROM dba_workload_connection_map;

b. Remap the connections:

EXEC DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (schedule_cap_id => 1,
conn_id => 1, replay_connection => 'CRM');
EXEC DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (schedule_cap_id => 2,
conn_id => 1, replay_connection => 'ERP');
EXEC DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (schedule_cap_id => 3,
conn_id => 1, replay_connection => 'SCM');

The replay_connection parameter represents the services that are defined on the test system.

c. Verify the connection remappings:

SELECT schedule_cap_id, conn_id, capture_conn, replay_conn
FROM dba_workload_connection_map;

9. Prepare the consolidated replay:

EXEC DBMS_WORKLOAD_REPLAY.PREPARE_CONSOLIDATED_REPLAY (
synchronization => 'OBJECT_ID');

10. Start replay clients:

a. Estimate the number of replay clients that are required:

wrc mode=calibrate replaydir=/u01/test/cons_dir/cap_crm
wrc mode=calibrate replaydir=/u01/test/cons_dir/cap_erp
wrc mode=calibrate replaydir=/u01/test/cons_dir/cap_scm

b. Add the output to determine the number of replay clients required.
You will need to start at least one replay client per workload capture contained in the consolidated workload.

c. Start the required number of replay clients by repeating this command:

wrc username/password mode=replay replaydir=/u01/test/cons_dir

The replaydir parameter is set to the root directory in which the workload captures are stored.

11. Start the consolidated replay:

EXEC DBMS_WORKLOAD_REPLAY.START_CONSOLIDATED_REPLAY;

See Also:

- Oracle Database Administrator's Guide for information about configuring a CDB

- Oracle Database Administrator's Guide for information about creating PDBs

16 Using Workload Scale-Up

This chapter describes using various workload scale-up techniques with Consolidated Database Replay and contains the following sections:

- Overview of Workload Scale-Up

- Using Time Shifting

- Using Workload Folding

- Using Schema Remapping

Overview of Workload Scale-Up

Consolidated Database Replay enables you to replay multiple workloads captured from one or multiple systems concurrently. During the replay, every workload capture that is consolidated will start to replay when the consolidated replay begins. Depending on the use case, you can employ various workload scale-up techniques when using Consolidated Database Replay. For information about typical use cases for Consolidated Database Replay, see "Use Cases for Consolidated Database Replay".

This section describes the following workload scale-up techniques:

- About Time Shifting

- About Workload Folding

- About Schema Remapping

About Time Shifting

Database Replay enables you to perform time shifting when replaying captured workloads. This technique is useful in cases where you want to conduct stress testing on a system by adding workloads to an existing workload capture and replaying them together.

For example, assume that there are three workloads captured from three applications: Sales, CRM, and DW. In order to perform stress testing, you can align the peaks of these workload captures and replay them together using Consolidated Database Replay.

See Also:

- "Using Time Shifting" for information about using time shifting

- "Stress Testing" for information about using Consolidated Database Replay for stress testing

About Workload Folding

Database Replay enables you to perform scale-up testing by folding an existing workload capture. For example, assume that a workload was captured from 2 a.m. to 8 p.m. You can use Database Replay to fold the original workload into three capture subsets: one from 2 a.m. to 8 a.m., a second from 8 a.m. to 2 p.m., and a third from 2 p.m. to 8 p.m. By replaying the three capture subsets together, you can fold the original capture and triple the workload during replay to perform scale-up testing.

See Also:

- "Using Workload Folding" for information about using workload folding

- "Capture Subsets" for information about capture subsets

- "Scale-Up Testing" for information about using Consolidated Database Replay for scale-up testing

About Schema Remapping

Database Replay enables you to perform scale-up testing by remapping database schemas. This technique is useful in cases when you are deploying multiple instances of the same application—such as a multi-tenet application—or adding a new geographical area to an existing application.

For example, assume that a single workload exists for a Sales application. To perform scale-up testing and identify possible host bottlenecks, set up the test system with multiple schemas from the Sales schema.

See Also:

- "Using Schema Remapping" for information about using schema remapping

- "Scale-Up Testing" for information about using Consolidated Database Replay for scale-up testing

Using Time Shifting

This section describes how to use time shifting with Consolidated Database Replay, and assumes a scenario where you want to use time shifting to align the peaks of workloads captured from three applications and replay them simultaneously. The scenario demonstrates how to use time shifting for stress testing. For more information about time shifting, see "About Time Shifting".

This scenario uses the following assumptions:

- The first workload is captured from the Sales application.

- The second workload is captured from the CRM application and its peak time occurs 1 hour before that of the Sales workload.

- The third workload is captured from the DW application and its peak time occurs 30 minutes before that of the Sales workload.

- To align the peaks of these workloads, time shifting is performed by adding a delay of one hour to the CRM workload and a delay of 30 minutes to the DW workload during replay.

To perform time shifting in this scenario:

1. On the replay system which will undergo stress testing, create a directory object for the root directory where the captured workloads are stored:

CREATE [OR REPLACE] DIRECTORY cons_dir AS '/u01/test/cons_dir';

2. Preprocess the individual workload captures into separate directories:

- For the Sales workload:

a. Create a directory object:

CREATE OR REPLACE DIRECTORY sales AS '/u01/test/cons_dir/cap_sales';

b. Ensure that the captured workload from the Sales application is stored in this directory.

c. Preprocess the workload:

EXEC DBMS_WORKLOAD_REPLAY.PROCESS_CAPTURE ('SALES');

- For the CRM workload:

a. Create a directory object:

CREATE OR REPLACE DIRECTORY crm AS '/u01/test/cons_dir/cap_crm';

b. Ensure that the captured workload from the CRM application is stored in this directory.

c. Preprocess the workload:

EXEC DBMS_WORKLOAD_REPLAY.PROCESS_CAPTURE ('CRM');

- For the DW workload:

a. Create a directory object:

CREATE OR REPLACE DIRECTORY DW AS '/u01/test/cons_dir/cap_dw';

b. Ensure that the captured workload from the DW application is stored in this directory.

c. Preprocess the workload:

EXEC DBMS_WORKLOAD_REPLAY.PROCESS_CAPTURE ('DW');

3. Set the replay directory to the root directory:

EXEC DBMS_WORKLOAD_REPLAY.SET_REPLAY_DIRECTORY ('CONS_DIR');

4. Create a replay schedule and add the workload captures:

EXEC DBMS_WORKLOAD_REPLAY.BEGIN_REPLAY_SCHEDULE ('align_peaks_schedule');
SELECT DBMS_WORKLOAD_REPLAY.ADD_CAPTURE ('SALES') FROM dual;
SELECT DBMS_WORKLOAD_REPLAY.ADD_CAPTURE ('CRM', 3600) FROM dual;
SELECT DBMS_WORKLOAD_REPLAY.ADD_CAPTURE ('DW', 1800) FROM dual;
EXEC DBMS_WORKLOAD_REPLAY.END_REPLAY_SCHEDULE;

Note that a delay of 3,600 seconds (or 1 hour) is added to the CRM workload, and a delay of 1,800 seconds (or 30 minutes) is added to the DW workload.

5. Initialize the consolidated replay:

EXEC DBMS_WORKLOAD_REPLAY.INITIALIZE_CONSOLIDATED_REPLAY ('align_peaks_replay',
'align_peaks_schedule');

6. Remap connections:

a. Query the DBA_WORKLOAD_CONNECTION_MAP view for the connection mapping information:

SELECT schedule_cap_id, conn_id, capture_conn, replay_conn
FROM dba_workload_connection_map;

b. Remap the connections:

EXEC DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (schedule_cap_id => 1,
conn_id => 1, replay_connection => 'inst1');
EXEC DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (schedule_cap_id => 1,
conn_id => 2, replay_connection => 'inst1');
EXEC DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (schedule_cap_id => 2,
conn_id => 1, replay_connection => 'inst2');
EXEC DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (schedule_cap_id => 2,
conn_id => 2, replay_connection => 'inst2');
EXEC DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (schedule_cap_id => 3,
conn_id => 1, replay_connection => 'inst3');
EXEC DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (schedule_cap_id => 3,
conn_id => 2, replay_connection => 'inst3');

The replay_connection parameter represents the services that are defined on the test system.

c. Verify the connection remappings:

SELECT schedule_cap_id, conn_id, capture_conn, replay_conn
FROM dba_workload_connection_map;

7. Prepare the consolidated replay:

EXEC DBMS_WORKLOAD_REPLAY.PREPARE_CONSOLIDATED_REPLAY;

8. Start replay clients:

a. Estimate the number of replay clients that are required:

wrc mode=calibrate replaydir=/u01/test/cons_dir/cap_sales
wrc mode=calibrate replaydir=/u01/test/cons_dir/cap_crm
wrc mode=calibrate replaydir=/u01/test/cons_dir/cap_dw

b. Add the output to determine the number of replay clients required.
You will need to start at least one replay client per workload capture contained in the consolidated workload.

c. Start the required number of replay clients by repeating this command:

wrc username/password mode=replay replaydir=/u01/test/cons_dir

The replaydir parameter is set to the root directory in which the workload captures are stored.

9. Start the consolidated replay:

EXEC DBMS_WORKLOAD_REPLAY.START_CONSOLIDATED_REPLAY;

Using Workload Folding

This section describes how to use workload folding with Consolidated Database Replay, and assumes a scenario where you want to use workload folding to triple a captured workload. The scenario demonstrates how to use workload folding for scale-up testing. For more information about workload folding, see "About Workload Folding".

This scenario uses the following assumptions:

- The original workload was captured from 2 a.m. to 8 p.m. and folded into three capture subsets.

- The first capture subset contains part of the original workload from 2 a.m. to 8 a.m.

- The second capture subset contains part of the original workload from 8 a.m. to 2 p.m.

- The third capture subset contains part of the original workload from 2 p.m. to 8 p.m.

- To triple the workload during replay, workload folding is performed by replaying the three capture subsets simultaneously.

To perform workload folding in this scenario:

1. On the replay system where you plan to perform scale-up testing, create a directory object for the root directory where the captured workloads are stored:

CREATE OR REPLACE DIRECTORY cons_dir AS '/u01/test/cons_dir';

2. Create a directory object for the directory where the original workload is stored:

CREATE OR REPLACE DIRECTORY cap_monday AS '/u01/test/cons_dir/cap_monday';

3. Create directory objects for the directories where you are planning to store the capture subsets:

a. Create a directory object for the first capture subset:

CREATE OR REPLACE DIRECTORY cap_mon_2am_8am
AS '/u01/test/cons_dir/cap_monday_2am_8am';

b. Create a directory object for the second capture subset:

CREATE OR REPLACE DIRECTORY cap_mon_8am_2pm
AS '/u01/test/cons_dir/cap_monday_8am_2pm';

c. Create a directory object for the third capture subset:

CREATE OR REPLACE DIRECTORY cap_mon_2pm_8pm
AS '/u01/test/cons_dir/cap_monday_2pm_8pm';

4. Create the capture subsets:

a. Generate the first capture subset for the time period from 2 a.m. to 8 a.m.:

EXEC DBMS_WORKLOAD_REPLAY.GENERATE_CAPTURE_SUBSET ('CAP_MONDAY',
'CAP_MON_2AM_8AM', 'mon_2am_8am_wkld',
0, TRUE, 21600, FALSE, 1);

b. Generate the second capture subset for the time period from 8 a.m. to 2 p.m.:

EXEC DBMS_WORKLOAD_REPLAY.GENERATE_CAPTURE_SUBSET ('CAP_MONDAY',
'CAP_MON_8AM_2PM', 'mon_8am_2pm_wkld',
21600, TRUE, 43200, FALSE, 1);

c. Generate the third capture subset for the time period from 2 p.m. to 8 p.m.:

EXEC DBMS_WORKLOAD_REPLAY.GENERATE_CAPTURE_SUBSET ('CAP_MONDAY',
'CAP_MON_2PM_8PM', 'mon_2pm_8pm_wkld',
43200, TRUE, 0, FALSE, 1);

5. Preprocess the capture subsets:

EXEC DBMS_WORKLOAD_REPLAY.PROCESS_CAPTURE ('CAP_MON_2AM_8AM');
EXEC DBMS_WORKLOAD_REPLAY.PROCESS_CAPTURE ('CAP_MON_8AM_2PM');
EXEC DBMS_WORKLOAD_REPLAY.PROCESS_CAPTURE ('CAP_MON_2PM_8PM');

6. Set the replay directory to the root directory:

EXEC DBMS_WORKLOAD_REPLAY.SET_REPLAY_DIRECTORY ('CONS_DIR');

7. Create a replay schedule and add the capture subsets:

EXEC DBMS_WORKLOAD_REPLAY.BEGIN_REPLAY_SCHEDULE ('monday_folded_schedule');
SELECT DBMS_WORKLOAD_REPLAY.ADD_CAPTURE ('CAP_MON_2AM_8AM') FROM dual;
SELECT DBMS_WORKLOAD_REPLAY.ADD_CAPTURE ('CAP_MON_8AM_2PM') FROM dual;
SELECT DBMS_WORKLOAD_REPLAY.ADD_CAPTURE ('CAP_MON_2PM_8PM') FROM dual;
EXEC DBMS_WORKLOAD_REPLAY.END_REPLAY_SCHEDULE;

8. Initialize the consolidated replay:

EXEC DBMS_WORKLOAD_REPLAY.INITIALIZE_CONSOLIDATED_REPLAY (
'monday_folded_replay', 'monday_folded_schedule');

9. Remap connections:

a. Query the DBA_WORKLOAD_CONNECTION_MAP view for the connection mapping information:

SELECT schedule_cap_id, conn_id, capture_conn, replay_conn
FROM dba_workload_connection_map;

b. Remap the connections:

EXEC DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (schedule_cap_id => 1,
conn_id => 1, replay_connection => 'inst1');
EXEC DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (schedule_cap_id => 1,
conn_id => 2, replay_connection => 'inst1');
EXEC DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (schedule_cap_id => 2,
conn_id => 1, replay_connection => 'inst2');
EXEC DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (schedule_cap_id => 2,
conn_id => 2, replay_connection => 'inst2');
EXEC DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (schedule_cap_id => 3,
conn_id => 1, replay_connection => 'inst3');
EXEC DBMS_WORKLOAD_REPLAY.REMAP_CONNECTION (schedule_cap_id => 3,
conn_id => 2, replay_connection => 'inst3');

The replay_connection parameter represents the services that are defined on the test system.

c. Verify the connection remappings:

SELECT schedule_cap_id, conn_id, capture_conn, replay_conn
FROM dba_workload_connection_map;

10. Prepare the consolidated replay:

EXEC DBMS_WORKLOAD_REPLAY.PREPARE_CONSOLIDATED_REPLAY;

11. Start replay clients:

a. Estimate the number of replay clients that are required:

wrc mode=calibrate replaydir=/u01/test/cons_dir/cap_monday_2am_8am
wrc mode=calibrate replaydir=/u01/test/cons_dir/cap_monday_8am_2pm
wrc mode=calibrate replaydir=/u01/test/cons_dir/cap_monday_2pm_8pm

b. Add the output to determine the number of replay clients required.
You will need to start at least one replay client per workload capture contained in the consolidated workload.

c. Start the required number of replay clients by repeating this command:

wrc username/password mode=replay replaydir=/u01/test/cons_dir

The replaydir parameter is set to the root directory in which the workload captures are stored.

12. Start the consolidated replay:

EXEC DBMS_WORKLOAD_REPLAY.START_CONSOLIDATED_REPLAY;

Using Schema Remapping

This section describes how to use schema remapping with Consolidated Database Replay, and assumes a scenario where you want to use schema remapping to identify possible host bottlenecks when deploying multiple instances of an application. The scenario demonstrates how to use schema remapping for scale-up testing. For more information about schema remapping, see "About Schema Remapping".

This scenario uses the following assumptions:

- A single workload exists that is captured from the Sales application.

- To set up the replay system with multiple schemas from the Sales schema, schema remapping is performed by adding the captured workload multiple times into a replay schedule and remapping the users to different schemas.

To perform schema remapping in this scenario:

1. On the replay system where you plan to perform scale-up testing, create a directory object for the root directory where the captured workloads are stored:

CREATE OR REPLACE DIRECTORY cons_dir AS '/u01/test/cons_dir';

2. Create a directory object for the directory where the captured workload is stored:

CREATE OR REPLACE DIRECTORY cap_sales AS '/u01/test/cons_dir/cap_sales';

Ensure that the captured workload from the Sales application is stored in this directory.

3. Preprocess the captured workload:

EXEC DBMS_WORKLOAD_REPLAY.PROCESS_CAPTURE ('CAP_SALES');

4. Set the replay directory to the root directory:

EXEC DBMS_WORKLOAD_REPLAY.SET_REPLAY_DIRECTORY ('CONS_DIR');

5. Create a replay schedule and add the captured workload multiple times:

EXEC DBMS_WORKLOAD_REPLAY.BEGIN_REPLAY_SCHEDULE ('double_sales_schedule');
SELECT DBMS_WORKLOAD_REPLAY.ADD_CAPTURE ('CAP_SALES') FROM dual;
SELECT DBMS_WORKLOAD_REPLAY.ADD_CAPTURE ('CAP_SALES') FROM dual;
EXEC DBMS_WORKLOAD_REPLAY.END_REPLAY_SCHEDULE;

6. Initialize the consolidated replay:

EXEC DBMS_WORKLOAD_REPLAY.INITIALIZE_CONSOLIDATED_REPLAY (
'double_sales_replay', 'double_sales_schedule);

7. Remap the users:

EXEC DBMS_WORKLOAD_REPLAY.SET_USER_MAPPING (2, 'sales_usr', 'sales_usr_2');

8. Prepare the consolidated replay:

EXEC DBMS_WORKLOAD_REPLAY.PREPARE_CONSOLIDATED_REPLAY;

9. Start replay clients:

a. Estimate the number of replay clients that are required:

wrc mode=calibrate replaydir=/u01/test/cons_dir/cap_sales

b. Add the output to determine the number of replay clients required.
You will need to start at least one replay client per workload capture contained in the consolidated workload.

c. Start the required number of replay clients by repeating this command:

wrc username/password mode=replay replaydir=/u01/test/cons_dir

The replaydir parameter is set to the root directory in which the workload captures are stored.

10. Start the consolidated replay:

EXEC DBMS_WORKLOAD_REPLAY.START_CONSOLIDATED_REPLAY;

Part III Test Data Management

Oracle Database offers test data management features that enable you to:

- Store the list of applications, tables, and relationships between table columns using Application Data Modeling

- Replicate information that pertains only to a particular site using data subsetting

- Replace sensitive data from your production system with fictitious data that can be used during testing using Oracle Data Masking

Part III covers test data management and contains the following chapters:

- Application Data Models

- Data Subsetting

- Masking Sensitive Data

17 Application Data Models

Secure Test Data Management provides Enterprise Manager the capability to enable operations such as sensitive data discovery, data subsetting, and data masking. These capabilities enable scanning and tagging of sensitive data and modeling of data relationships incorporated within an Application Data Model (ADM). You must have the Oracle Data Masking and Subsetting Pack license to use test data management features.

The ADM stores the list of applications, tables, and relationships between table columns that are either declared in the data dictionary, imported from application metadata, or user-specified. The ADM maintains sensitive data types and their associated columns, and is used by test data operations, such as data subsetting and data masking, to securely produce test data. Creating an ADM is a prerequisite for data subsetting and data masking operations.

Figure 17-1 shows the Application Data Model's relationship to other test data management components as well as the production and test environments.

Figure 17-1 Test Data Management Architecture

You can perform several tasks related to Application Data Modeling, including the following tasks discussed in this chapter:

- Creating an Application Data Model

- Managing Sensitive Column Types

- Associating a Database to an Application Data Model

- Importing and Exporting an Application Data Model

- Verifying or Upgrading a Source Database

- Using Self Update to Download the Latest Data Masking and Test Data Management Templates

- Test Data Management and Access Rights

- Granting Privileges on an Application Data Model

Note:

The procedures in this chapter are applicable to Oracle Enterprise Manager 12.1 and higher Cloud Control only.

See Also:

- Data Subsetting, for information about data subsetting

- Masking Sensitive Data, for information about data masking

Creating an Application Data Model

The following procedure enables you to:

- Initiate creation of an Application Data Model (ADM)

- View and edit application tables

- View referential relationships

- Manually add a referential relationship

- Discover sensitive columns

- Set the type for sensitive columns

Before proceeding, ensure that you have the following privileges:

- EM_ALL_OPERATOR for Enterprise Manager Cloud Control users

- SELECT_CATALOG_ROLE for database users

- Select Any Dictionary privilege for database users

Note:

When you create an ADM, the PL/SQL metadata collection packages are automatically deployed on the target database. The Database user must have DBA privileges to auto-deploy the packages.

To create an Application Data Model:

1. From the Application Data Models page, view the diagram that shows how you can create a database for a test environment.
As the diagram shows, the first step is to create an ADM.

2. Create an ADM:

a. Click Create.
A pop-up window requesting general properties information appears.

b. Provide the required Name and Source Database.
The Source Database is the source from which the metadata is to be extracted.

c. Select an Application Suite:
If you select Custom Application Suite:

- By default, metadata collection is enabled for the ADM creation process.

- If you uncheck "Create One Application For Each Schema," you create a shell ADM and will need to edit the ADM later to add applications and tables. Also, no metadata collection job is submitted, unlike the default choice.

If you select Oracle Application Suite:

- Oracle E-Business Suite–You provide database credentials for APPS user (or equivalent) and submit a job to create the ADM.

- Oracle Fusion Applications–You provide database credentials for FUSION user (or equivalent) and submit a job to create the ADM.

Note the following points about metadata collections:

- The metadata collection for the selected application suite populates the ADM with the applications and tables in the suite.

- The ADM can collect metadata for one or more schemas. An ADM application typically represents a schema. Each schema you select becomes an ADM application, and the ADM becomes populated with the tables in the schema, particularly in the case of custom applications. Note, however, that multiple applications can also map to a single schema, as in the case of Fusion Applications. The actual mapping depends on the application metadata discovered by the metadata collection job.

d. Click Continue.
Assuming that you selected Custom Application Suite, a Schemas pop-up appears in which you select schemas to include from the Available list.

e. Click Continue, provide the schedule parameters, then click Submit to submit the metadata collection job.
The ADM you created appears in the Application Data Models page. The Most Recent Job Status table column indicates that the metadata collection job is running. The model is locked, and you cannot edit it during this period until the status indicates that the job is complete.

3. View and edit application tables:

a. Select the model you created, then select Edit.
The Applications and Tables subpage appears, displaying the applications found during metadata collection.

To see the tables for an application, click the expand ( > ) icon.

b. To edit an application, select the application, open the Actions menu, then select Add Table to Application.
The Add Table to Application pop-up window appears.

c. Click the Table search icon.
The Search and Select pop-up appears, showing all of the tables from the selected schema that are not assigned to an application.

d. Select an unassigned table, then click OK.
The table name now appears in the Add Table to Application pop-up.

e. After selecting a Table Type, click OK.
The table now appears in the Applications and Tables view.

4. View referential relationships:

a. Click the Referential Relationships tab.
There are three types of referential relationships:

- Dictionary-defined
Upon opening this tab, this view shows the referential relationships that the metadata collection extracted, resulting from primary key and foreign key relationships. You can remove relationships from the ADM if desired.

- Imported from template
If there are application templates available from the vendor of the enterprise application, for example, Oracle Fusion Applications or Oracle E-Business Suite, then the ADM can be created from the application vendor-supplied template by using the Import action on the ADM home page.

- User-defined
See the step below about manually adding a referential relationship for more information.

b. Open an application view by selecting it, then using the chevron icon (>) to reveal parent and dependent key relationships, or by selecting Expand All from the View menu to view all relationships.

5. Manually add a referential relationship:

a. From the Referential Relationships tab, open the Actions menu, then select Add Referential Relationship.
The Add Referential Relationship pop-up window appears.

b. Select the requisite Parent Key and Dependent Key information.

c. In the Columns Name list, select a dependent key column to associate with a parent key column.

d. Click OK to add the referential relationship to the ADM.
The new dependent column now appears in the referential relationships list.

6. Discover sensitive columns automatically or add them manually:

To automatically discover sensitive columns:

a. From the Sensitive Columns tab, open the Actions menu, then select Create Sensitive Column Discovery Job.
The Parameters pop-up appears.

b. Select one or more applications and one or more sensitive column types.
Each type you select is processed for each application to search for columns that match the type.

c. Click Continue.
The schedule pop-up window appears.

d. Provide the required information, schedule the job, then click Submit when you have finished.
The Sensitive Columns subpage reappears.

e. Click Save and Return to return to the Application Data Models home page.

f. When the Most Recent Job Status column indicates that the job is Successful, select the ADM, then click Edit.

g. Select the Sensitive Columns tab, then click Discovery Results to view the job results.

h. To set the sensitive status of any column, select the row for the column you want to define, open the Set Status menu, then select either Sensitive or Not Sensitive.

i. Click OK to save and return to the Sensitive Columns tab.
The sensitive columns you defined in the previous step now appear in the list.

j. Click Save and Return to return to the Application Data Models page.

To manually add sensitive columns:

a. From the Application Data Models page, select an ADM, then click Edit.

b. Select the Sensitive Columns tab, then click Add.
The Add Sensitive Column pop-up appears.

c. Provide the required information and an optional Sensitive Column Type, then click OK.
The sensitive column now appears in the table for the Sensitive Columns tab.

7. Change the type for sensitive columns:

a. Click the Sensitive Columns tab.
This view shows the sensitive columns that have already been identified.

b. Select the sensitive column for which you want to change the type.

c. Open the Actions menu, then select Set Sensitive Column Type.
The Set Sensitive Column Type pop-up window appears.

d. Select the new type and click OK.

Managing Sensitive Column Types

After you have successfully created an ADM, the next task is to create either a new sensitive column type or one based on an existing type.

To create a sensitive column type:

1. From the Actions menu of the Application Data Models page, select Sensitive Column Types.
The Sensitive Column Types page appears.

2. Click Create.
The Create Sensitive Column Type pop-up appears.

3. Specify a required name and regular expressions for the Column Name, Column Comment, and Column Data search patterns.

- The Or Search Type means that any of the patterns can match for a candidate sensitive column.

- The And Search Type means that all of the patterns must match for a candidate sensitive column.

If you do not provide expressions for any of these parameters, the system does not search for the entity.

4. Click OK.
The sensitive column appears in the table in the Sensitive Column Types page.

To create a sensitive column type based on an existing type:

1. From the Actions menu of the Application Data Models page, select Sensitive Column Types.
The Sensitive Column Types page appears.

2. Select either a sensitive column type you have already defined, or select one from the out-of-box types that the product provides.

3. Click Create Like.
The Create Sensitive Column Type pop-up appears.

4. Specify a required name and alter the existing expressions for the Column Name, Column Comment, and Column Data search patterns to suit your needs.

5. Click OK.
The sensitive column appears in the table in the Sensitive Column Types page.

Associating a Database to an Application Data Model

After you have created an Application Data Model (ADM), you can select additional databases to be associated databases of an ADM, as explained in the following procedure. See "Creating an Application Data Model" for instructions on creating an ADM.

To associate a database to an ADM:

1. From the Application Data Models page, select an ADM, select Actions, then Associated Databases.
This dialog lists all of the databases associated with this ADM and the schemas assigned to each application per database. You can add more databases that give you a choice of data sources when subsetting and databases to mask during masking.

2. Click Add, then select a database from the pop-up.
The selected database now appears in the Database section of the Associated Databases dialog.

3. To change a schema, select the associated database on the left, select the application on the right for which the schema is to be changed, then click Select Schema.

4. Select the missing schema from the list in the pop-up, then click Select.

Importing and Exporting an Application Data Model

You can share Application Data Models (ADM) with other Enterprise Manager environments that use a different repository by exporting an ADM, which can subsequently be imported into the new repository.

An exported ADM is by definition in the XML file format required for import. You can edit an exported ADM XML file prior to import. When exporting an ADM for subsequent import, it is best to have one that uses most or all of the features—applications, tables, table types, referential relationships, sensitive columns. This way, if you are going to edit the exported file prior to import, it is clear which XML tags are required and where they belong in the file.

- Importing an ADM

- Exporting an ADM

Note:

There are EMCLI verbs to export and import an ADM if you want to perform these operations remotely or script them.

Importing an ADM

There are two methods of import:

- Import an ADM XML file from the desktop

- Import an ADM XML file from the Software Library

To import an ADM XML file from your desktop:

1. From the Actions menu, select Import, then select File from Desktop.

2. In the pop-up that appears, specify a name for the ADM, the source database you want to assign to the ADM, and location on your desktop from which you want to import the ADM.

3. Click OK.
The ADM now appears on the Application Data Models page.

To import an ADM XML file from the Software Library:

1. From the Actions menu, select Import, then select File from Software Library.

2. In the Export File from Software Library pop-up that appears, select the desired ADM XML file on the left, then specify a name and the source database you want to assign to the ADM on the right.

3. Click Import.

The ADM now appears on the Application Data Models page.

After importing an ADM, you may want to discover sensitive columns or run a verification job. In the process of performing these tasks, the PL/SQL metadata collection packages are automatically deployed on the target database. The Database user must have DBA privileges to auto-deploy the packages.

Exporting an ADM

There are three methods of export:

- Export a selected ADM to the desktop

- Export an ADM from the Software Library

- Export an ADM to a TSDP Catalog

To export an ADM as an XML file to your desktop:

1. From the Application Data Models page, select the ADM you want to export.

2. From the Actions menu, select Export, then select Selected Application Data Model.

3. In the File Download pop-up that appears, click Save.

4. In the Save As pop-up that appears, navigate to a file location and click Save.
The system converts the ADM into an XML file that now appears at the specified location on your desktop.

To export an ADM from the Software Library:

1. From the Actions menu, select Export, then select File from Software Library.

2. In the Export File from Software Library pop-up that appears, select the desired ADM and click Export.

3. In the File Download pop-up that appears, click Save.

4. In the Save As pop-up that appears, navigate to a file location and click Save.
The system converts the ADM into an XML file that now appears at the specified location on your desktop.

To export an ADM to a Transparent Sensitive Data Protection (TSDP) Catalog:

1. From the Application Data Models page, select the ADM you want to export.

2. From the Actions menu, select Export, then select Export to TSDP Catalog.

3. The Application Data Models page displays a table of associated databases. Select a database and click the Export Sensitive Data button.

4. In the Export Sensitive Data pop-up that appears, provide credentials for the selected database and click OK.

A message appears on the Application Data Models page confirming that the sensitive data was copied to the database.

For detailed information on TSDP, see Oracle Database Security Guide.

Verifying or Upgrading a Source Database

After you have created an Application Data Model (ADM), the Source Database Status column can indicate Valid, Invalid, Needs Verification, or Needs Upgrade.

- Invalid status–Verify the source database to update the referential relationships in the application data model with those found in the data dictionary, and to also determine if each item in the application data model has a corresponding object in the database.

- Needs Verification status–You have imported an Oracle supplied template and you must verify the ADM before you can use it. This is to ensure that necessary referential relationships from data dictionary are pulled into the ADM.

- Needs Upgrade status–You have imported a pre-12c masking definition, so you now need to upgrade the ADM.

To verify a source database:

1. Select the ADM to be verified, indicated with an Invalid status.

2. From the Actions menu, select Verify.

3. Select the source database with the Invalid status, then click Create Verification Job.

4. Specify job parameters in the Create Verification Job pop-up, then click Submit.

5. After the job completes successfully, click the source database and note the object problems listed.

6. Fix the object problems, rerun the Verification Job, then check that the Source Database Status is now Valid.

To upgrade an ADM:

1. Select the ADM to be upgraded, indicated with a Needs Upgrade status.

2. From the Actions menu, select Upgrade.

3. Specify job parameters in the Create Upgrade Job pop-up, then click Submit.

4. After the job completes successfully, check that the Source Database Status column now indicates Valid. If the column indicates Invalid, see the previous procedure.

Using Self Update to Download the Latest Data Masking and Test Data Management Templates

Use the Self Update feature to get the latest data masking and data subsetting templates available from Oracle, out of band of the next major release cycle. With the auto-download feature enabled, new templates appear in the Software Library as they become available. Otherwise, you can access them manually as follows:

1. From the Setup menu, select Extensibility, then select Self Update.

2. On the Self Update page, scroll down and select Test Data Management templates.

3. In the available updates table, select the templates you want to download and select Download from the Actions menu.
This action downloads the templates to the Software Library from where you can import them into your Data Masking and Test Data Management environment or save them locally for editing.

4. To save a downloaded template:

a. Navigate to the appropriate home page (ADM, masking, or subset).

b. From the Actions menu, select Export from the Software Library.

c. Select a template in the pop-up window and click Save.

d. Specify a location where to save the XML file.

The template file is available for editing prior to being imported into Application Data Models.

5. To import a downloaded template:

a. Navigate to the appropriate home page (ADM, masking, or subset).

b. From the Actions menu, select Import from the Software Library.

c. Select a template in the pop-up window and specify appropriate values for the input parameters.

d. Click Import. Template definitions are imported into the respective tables.

Reapply Templates if Upgrading to Database Plug-in 12.1.0.5 from Release 12.1.0.3 or 12.1.0.4

If you previously applied test data management templates and are upgrading from release 12.1.0.3 or 12.1.0.4, you have to remove the templates and then reapply them; otherwise, the templates will not be visible when importing or exporting from the Software Library.

1. Go to the Self Update page.

2. Select the test data management templates and remove them.

3. Return to the Self Update page.

4. Select the test data management templates and check for updates.

5. In the available updates table, select the templates you want and then download and apply them using the respective actions from the Actions menu.
The templates should now be visible in the Software Library.

Test Data Management and Access Rights

By default, Enterprise Manager Administrators can access the primary test data management (TDM) pages:

- Application Data Models

- Data Subset Definitions

- Data Masking Definitions

- Data Masking Formats

This is by virtue of having the TDM_ACCESS privilege, which is included in the PUBLIC role. The Super Administrator can revoke this privilege for designated administrators, thereby restricting access to the TDM pages. Without the privilege, the respective menu items do not appear in the Cloud Control console.

Additionally, Enterprise Manager provides a privilege access model that enables Super Administrators and administrators to limit access to TDM objects to authorized users only. The model involves the ability to grant Operator or Designer privileges to selected users.

Operator Privileges

Those granted Operator privileges can perform data masking and subsetting operations. Privileges can be granted on TDM objects; that is, on Application Data Models (ADM), data subsetting definitions, and data masking definitions. Operator privileges do not include the ability to edit and delete these objects.

- ADM–a user (other than Super Administrator) with ADM Operator privileges can view an ADM but cannot edit and delete it, nor view its properties. To enforce this, the Edit and Delete icons, and the Properties menu are disabled. Additionally, the Sync option on the Create Verification Job page is disabled.

- Data subset definition–a user (other than Super DSD Administrator) with Operator privileges can view but not edit and delete a subset definition. To enforce this, the Edit and Delete icons are disabled.
A user with Data Subset Definition Operator privileges can do any other operation except edit and delete the data subset definition and has the following rights:

- View the data subset definition.

- Create a data subset to export files.

- Create a data subset on a database.

- Save the subset script.

- Data masking definition–a user with Data Masking Definition Operator privileges can do any other operation except edit and delete the data masking definition and has the following rights:

- View the data masking definition.

- Generate a data masking script.

- Schedule a data masking job.

- Export a data masking definition.

Designer Privileges

Those granted Designer privileges can enhance, modify, and manage TDM objects. These users can also grant and revoke Operator and Designer privileges to others. Designer privileges imply the corresponding Operator privileges on a TDM object.

- ADM–a user with Designer privileges can perform all operations on an ADM including delete.

- Data subset definition–a user with Designer privileges can perform all operations on a subset definition including delete.

- Data masking definition–a user with Designer privileges can perform all operations on a masking definition including delete.

Granting Privileges on an Application Data Model

You can grant privileges on an Application Data Model that you create so that others can have access. To do so, you must be an Enterprise Manager Administrator with at least Designer privileges on the ADM.

1. From the Enterprise menu, select Quality Management, then select Application Data Models.

2. Select the ADM to which you want to grant privileges.

3. From the Actions menu, select Grant, then select as follows:

- Operator–to grant Operator privileges on the ADM to selected roles or administrators, which means the grantees can view and copy but not edit and delete the definition.

- Designer–to grant Designer privileges on the ADM to selected roles or administrators, which means the grantees can view, edit, and delete the definition.

4. In the dialog that opens, select the type (administrator or role, or both). Search by name, if desired. Make your selections and click Select.

Those selected now have privileges on the ADM.

5. Use the Revoke action if you want to deny privileges previously granted.

18 Data Subsetting

This chapter describes how to perform the following tasks:

- Creating a Data Subset Definition

- Importing and Exporting Subset Templates and Dumps

- Creating a Subset Version of a Target Database

- Synchronizing a Subset Definition with an Application Data Model

- Granting Privileges on a Subset Definition

The chapter also introduces the concept of inline masking and subsetting (About Inline Masking and Subsetting), and outlines a number of Inline Masking and Subsetting Scenarios.

You must have the Oracle Data Masking and Subsetting Pack license to use data subsetting features.

Note:

Data subsetting is supported only in Oracle Database versions 10.1 and higher. The procedures in this chapter are applicable only to Oracle Enterprise Manager Cloud Control 12.1 and higher.

Creating a Data Subset Definition

The procedure described in this section enables you to create a subset database, after which you can perform other tasks, such as editing the properties of the subset definition or exporting a subset definition.

The interface also allows you to perform inline, or at the source, masking while creating the subset definition.

Before proceeding, ensure that you have the following privileges:

- EM_ALL_OPERATOR for Enterprise Manager Cloud Control users

- SELECT_CATALOG_ROLE for database users

- SELECT_ANY_DICTIONARY privilege for database users

- Additionally, to perform an in-place delete operation, the DBA user must be granted the EXECUTE_ANY_TYPE privilege

To create a data subset definition:

1. From the Enterprise menu, select Quality Management, then Data Subset Definitions.

2. Open the Actions menu in the Data Subset Definitions page, then select Create, or just click the Create icon.

3. Define the data subset definition properties:

a. Provide the requisite information in the General pop-up that appears, then click Continue.
You can select any source database associated with the Application Data Model.

If you are performing masking within the subset definition, you must select the same ADM and target used in creating the masking definition.

b. Provide a job name, credentials, and specify a schedule in the Schedule Application Detail Collection pop-up that appears, then click Submit.
If you want to use new credentials, choose the New Credentials option. Otherwise, choose the Preferred Credentials or Named Credentials option.

The space estimate collection job runs, and then displays the Data Subset Definitions page. Your definition appears in the table, and the Most Recent Job Status column should indicate Scheduled, Running, or Succeeded, depending on the schedule option selected and time required to complete the job.

4. Select the definition within the table, open the Actions menu, then select Edit.
The Database Login page appears.

5. Select either Named Credentials or New Credentials if you have not already set preferred credentials, then click Login.

6. In the Applications subpage of the Edit page, move applications from the Available list to the Selected list as follows:

- If you intend only to mask the data (no subsetting), select all applications.

- If you intend only to subset the data (no masking), select specific applications as appropriate.

- If you intend both to subset and mask the data, the applications selected must include those that the masking definitions require.

The names of application suites, applications, or application modules are maintained in the Application Data Model.

7. Click the Table Rules tab.

Note:

If you are masking only, set the Default Table Rules option to include all rows and skip to Step 13. The Column Rules tab, Rule Parameters tab, and additional features on the Table Rules tab pertain specifically to subsetting.

You can add rules here to define the data to include in the subset.

8. Select Actions, then Create to display the Table Rule pop-up, or just click the Create icon.

a. Select the application for which you want to provide a rule.
Associate the rule with all tables, a specific table, or a category of tables.

b. In the Rows to Include section, select the option that best suits your needs for a representative sample of production data. If you do not want to include all rows, you can include some rows by specifying a percentage portion of the rows. For finer granularity, you could specify a Where clause, such as where region_id=6.
For more information on specifying Where clauses, see Step 8.e.

c. In the Include Related Rows section, do one of the following:

- Select Ancestor and Descendant Tables
This rule impacts the parent and child columns, and ensures that referential integrity is maintained, and that child columns are also selected as part of the subset.

- Select Ancestor Tables Only
This rule only impacts the parent columns, and ensures that referential integrity is maintained.

If you disable the Include Related Rows check box, referential integrity may not be maintained. However, you can subsequently provide additional rules to restore referential integrity. You can disable this check box whether or not you specify a Where clause.

d. If you want to specify a Where clause, go to the next step. Otherwise, skip to Step 9.

e. Provide a rule parameter, if desired, for the clause.

For instance, if you specify a particular value for an employee ID as employee_id=:emp_id, you could enter query values for the default of 100:

- Select the Rows Where button and enter employee_id=:emp_id.

- Click OK to save the rule and return to the Table Rules tab.
If this is a new rule, a warning appears stating that "Rule parameters corresponding to the bind variables 'emp_id' should be created before generating subset."

- Select the table rule, click the Rule Parameters tab, then click Create.
The Rule Parameter Properties pop-up appears.

- Enter emp_id for the Name and 100 for the Value.

Note:

The colon ( : ) preceding emp_id is only present in the Where clause, and not required when creating a new rule parameter.

- Click OK to save the properties, which now appear in the Rule Parameters tab.

- Skip to Step 10.

9. Click OK to save the rule and return to the Table Rules tab.

The new rule is displayed in the list. The related tables are displayed in the table below. Related rows from the tables are included in the subset to provide referential integrity in the subset database.

10. In the Related Tables section of the Table Rules tab, you can manage the size of the subset by controlling the levels of ancestors and descendants within the subset. Notice that each node in the table has a check box. By default, all nodes are included in the subset, as indicated by the check mark. Deselect the check box to exclude a node from the subset. The deselection option is disabled for parent rows (the join columns to the right identify parent and child rows). In addition, you can make these other refinements to subset content:

- Click Allow Excluding Parent Tables. This enables the check marks that were grayed out. You can now selectively exclude parent rows from the subset by deselecting the check box.

- Select a node within the table and click Add Descendants to include related rows. In the dialog that opens, make appropriate selections and click OK.

As you make these refinements, columns on the right reflect the effect on space estimates for the subset. The Related Tables section also denotes the processing order of the ancestor and descendant tables, including the detailed impact of including each table. When you are done with the refinements, go to the Space Estimates tab to see a finer granularity of the impact on the overall size of the subset.

11. In the Default Table Rows section of the Table Rules tab, choose whether you want to include or exclude the tables not affected by the defined rules in the subset.
When you select the Include All Rows option, all of the rows for the table are selected as part of the subset.

This is a global rule and applies to the entire subset. You can only select the Include All Rows option when all of the rules have a scope of None. A scope of None is established when you uncheck the Include Related Rows option in the Table Rule pop-up.

Note:

For a subset definition that has column rules (see Step 12), be sure to use table rules to include the corresponding tables. You can use the Default Table Rules option to include all tables not affected by table rules, if required.

12. Optional: Click the Column Rules tab to perform inline masking as part of the subset definition.

a. Click Create and enter search criteria to filter on columns within the schema. These would typically be vertical columns such as CLOB AND BLOB columns.

Note:

If you are using column rules instead of masking definitions (see Step 13), you can select no more than 10 columns in a given table. This restriction applies to the export method but not to the in-place delete method.

Click OK.

b. Select a row or rows in the column search results and click Manage Masking Formats.

c. In the pop-up dialog, select a masking format and value to apply to the columns. For multiselection, the same format must be appropriate for all columns. If you select multiple columns, ensure that the column rule format you choose is applicable to the selected columns. Use the columns (flags) not null and unique to enforce compliance.
Click OK to apply the masking format to the columns.

13. Optional: Click the Data Masking tab to include masking definitions as part of the subsetting operation or to perform at the source data masking only.

a. Click Add.

b. In the pop-up dialog, enter search criteria to retrieve appropriate definitions. Be sure to select the desired radio button (All or Any). All formats except compound masking are supported for inline masking.

Note:

No single table within a masking definition can have more than 10 masked columns if you are using the export method. The restriction does not apply to the in-place delete method.

Click OK.

The search results appear in the data masking table.

14. Click the Space Estimates tab.

- Note the value in the Estimated Subset Size MB column. The space estimates depend on optimizer statistics, and the actual distribution of data can only be calculated if histogram statistics are present.

- Whenever you add new rules, recheck the space estimates for updated values.

- Data in the Space Estimates subpage is sorted with the largest applications appearing at the top.

Note:

Space estimates do not reflect the effect of data masking, if used.

If you provide a Where clause and subsequent rule parameter properties, the Space Estimates subpage is updated with the value contained in the Rule Parameters tab.

15. Optional: click the Pre/Post Subset Scripts tab.

- You can specify a pre-subset script to run on the subset database before you select subset data.

- You can specify a post-subset script to run on the subset database after you assemble the subset data.

- Either script type runs on the source database.

16. Click Return.
The definition is complete and displayed in the Data Subset Definitions table.

You can now proceed with script generation. Alternatively, you may want to save the script for future use. In either case, you must decide whether to export data to a dump file or delete data from a target database.

Tip:

If you have a very large database of 4 terabytes, for instance, and you want to export a small percentage of the rows, such as 10%, it is more advantageous to use the export method. Using the in-place delete method would require 3.6 terabytes of data, which would not perform as quickly as the export method.

The in-place delete method is recommended when the amount of data being deleted is a small percentage of the overall data size.

There is an EMCLI verb if you want to perform an in-place delete remotely or script it.

- Generating a Subset Script

- Saving a Subset Script

Generating a Subset Script

To prepare and submit a job to generate a subset script:

1. Select the definition within the table, open the Actions menu, then select Generate Subset. The Subset Mode pop-up appears.

2. Select a target database that is either the same target database you used to create the subset model, or similar to this database regarding the table schema and objects.

3. Decide if you want to create a subset by writing subset data to export files, or by deleting data from a target database.

Choosing to delete data creates an in-place subset by removing/deleting unwanted data from a cloned copy of the production database, rather than a production database. Only data satisfying the rules are retained. You should never use this option on a production database.

Select either Named Credentials or New Credentials if you have not already set preferred credentials.

If you have defined any parameters from the Rule Parameters tab, they appear in the table at the bottom. You can change a parameter value by clicking on the associated field in the Value column.

4. Click Continue to access the Parameters pop-up. The contents of the pop-up depend on whether you chose the export or delete option in the previous step.

For Writing Subset Data to Export Files, provide the requisite information, then click Continue to schedule the job.

- Specify a subset directory where to save the export dump. The drop-down list consists of directory objects for which you have access. Alternatively, you can select a custom directory path. Click the check box if you want to speed the process by using an external directory. Recommended default: DATA_PUMP_DIR.

- Specify appropriate values if you want to override the defaults: enter a name for the export file; specify a maximum file size in megabytes; specify the maximum number of threads of active execution operating on behalf of the export job. This enables you to consider trade-offs between resource consumption and elapsed time.

- Select whether to enable dump file compression and encryption. Enter and confirm an encryption password, if appropriate. Log file generation is selected by default.

For Deleting Data From a Target Database, provide the requisite information, then click Continue to schedule the job.

- Specify a subset directory where to save the subset scripts. The drop-down list consists of directory objects for which you have access. Alternatively, you can select a custom directory path. Recommended default: DATA_FILE_DIR.

- You must enable the check box indicating that the selected target is not a production database in order to proceed.

5. Click Continue to schedule the job from the Generate Subset Schedule pop-up, then click Submit. For the delete option, you must specify and confirm an encryption seed.

The Data Subset Definitions page reappears, and the Most Recent Job Status column shows that the subset job is running, and subsequently that it has succeeded.

After performing this procedure, you can now create a subset database with the generated export files at any time.

Saving a Subset Script

To prepare and submit a job to save a subset script:

1. Select the definition within the table, open the Actions menu, then select Save Subset Script. The Subset Mode pop-up appears.

2. Select a target database that is either the same target database you used to create the subset model, or similar to this database regarding the table schema and objects.

3. Decide if you want to create a subset by writing subset data to export files, or by deleting data from a target database.
Choosing to delete data creates an in-place subset by removing/deleting unwanted data from a cloned copy of the production database, rather than a production database. Only data satisfying the rules are retained. You should never use this option on a production database.

Select either Named Credentials or New Credentials if you have not already set preferred credentials.

If you have defined any parameters from the Rule Parameters tab, they appear in the table at the bottom. You can change a parameter value by clicking on the associated field in the Value column.

4. Click Continue to access the Parameters pop-up. The contents of the pop-up depend on whether you chose the export or delete option in the previous step.
For Writing Subset Data to Export Files, provide the requisite information, then click Continue to schedule the job.

- Specify a subset directory where to save the export dump. The drop-down list consists of directory objects for which you have access. Alternatively, you can select a custom directory path. Click the check box if you want to speed the process by using an external directory. Recommended default: DATA_PUMP_DIR.

- Specify appropriate values if you want to override the defaults: enter a name for the export file; specify a maximum file size in megabytes; specify the maximum number of threads of active execution operating on behalf of the export job. This enables you to consider trade-offs between resource consumption and elapsed time.

- Select whether to enable dump file compression and encryption. Enter and confirm an encryption password, if appropriate. Log file generation is selected by default.

For Deleting Data From a Target Database, provide the requisite information, then click Continue to schedule the job.

- Specify a subset directory where to save the subset scripts. The drop-down list consists of directory objects for which you have access. Alternatively, you can select a custom directory path. Recommended default: DATA_FILE_DIR.

- You must enable the check box indicating that the selected target is not a production database in order to proceed.

5. Click Continue. A progress indicator tracks script generation. When complete, the Files table lists the results of script generation.

6. Click Download. In the File Download pop-up that appears, click Save.

7. In the Save As pop-up that appears, navigate to a file location and click Save.
The file containing the scripts (SubsetBundle.zip) now appears at the specified location on your desktop.

To run the saved script at a later time:

1. Port the ZIP file to the target database and extract it to a directory on which you have the requisite privileges.

2. Change directory to where you extracted the files.

3. Execute the following script from the SQL command line:

subset_exec.sql

Note that if you want to change generated parameter settings, you can do so by editing the following file in a text editor prior to executing the script:

subset_exec_params.lst

Importing and Exporting Subset Templates and Dumps

A subset template is an XML file that contains the details of the subset, consisting of the application, subset rules, rule parameters, and pre-scripts or post-scripts. When you create a subset definition and specify that you want to write subset data to export files, the export files become a template that you can subsequently import for reuse. You would import the template to perform subset operations on a different database.

Typically, the workflow is that you would first import a previously exported ADM template, which is another XML file, while creating an ADM. You would then import the related subset template while creating a data subset definition. You could alternatively select an existing ADM (skipping the import ADM flow) while importing the subset template.

- Importing a Subset Definition

- Exporting a Subset Definition

Note:

There are EMCLI verbs to export and import subset definitions and subset dumps if you want to perform these operations remotely or script them.

Importing a Subset Definition

There are three methods of import:

- Import a subset definition XML file from the desktop

- Import a subset dump

- Import a subset definition XML file from the Software Library

To import a subset definition XML file from your desktop:

1. From the Actions menu, select Import, then select File from Desktop.

2. In the pop-up that appears:

- Specify a name for the subset definition

- The ADM on which the subset is based

- A source database

- The location on your desktop from which you want to import the subset definition

- Click Continue

3. In the pop-up that appears:

- Enter a descriptive job name (or accept the default)

- Provide credentials

- Schedule the job

- Click Submit

After the job runs successfully, the imported subset appears in the list of subsets in the table on the Data Subset Definitions page.

To import a subset dump:

1. From the Actions menu, select Import, then select Subset Dump.

2. In the pop-up that appears:

- Select a target database

- Provide database and host credentials, then click Login.

- Specify the location of the dump file, which can be in a selected directory on the target database or at a custom path on the target. Note that if the original export action used an external location for the dump files, the location must be specified as well.

- Click Continue.

3. In the pop-up that appears:

- Select whether to import both metadata and data, or data only. If data only, indicate if you want to truncate, that is, overlay existing data or append to existing data.

- Perform tablespace remapping as necessary

- Perform schema remapping as necessary

- Select log file options

- Click Continue

4. In the pop-up that appears:

- Enter a descriptive job name (or accept the default)

- Schedule the job

- Click Submit

The job reads the dump files and loads the data into the selected target database.

To import a subset definition XML file from the Software Library:

1. From the Actions menu, select Import, then select File from Software Library.

2. In the Import Data Subset Definition from Software Library pop-up that appears:

- Selected the desired subset definition XML file on the left

- Provide the ADM properties on the right.

- Click Continue

3. In the pop-up that appears:

- Enter a descriptive job name (or accept the default)

- Provide credentials

- Schedule the job

- Click Submit

After the job runs successfully, the imported subset appears in the list of subsets in the table on the Data Subset Definitions page.

Exporting a Subset Definition

There are two methods of export:

- Export a selected subset definition to the desktop

- Export a subset definition from the Software Library

To export a subset definition as an XML file to your desktop:

1. From the Data Subset Definitions page, select the subset definition you want to export.

2. From the Actions menu, select Export, then select Selected Subset Definition.

3. In the File Download pop-up that appears, click Save.

4. In the Save As pop-up that appears, navigate to a file location and click Save.
The system converts the subset definition into an XML file that now appears at the specified location on your desktop.

To export a subset definition from the Software Library:

1. From the Actions menu, select Export, then select File from Software Library.

2. In the Export Subset Definition from Software Library pop-up that appears, select the desired subset definition and click Export.

3. In the File Download pop-up that appears, click Save.

4. In the Save As pop-up that appears, navigate to a file location and click Save.

The system converts the subset definition into an XML file that now appears at the specified location on your desktop.

After the job runs successfully, the subset template appears in the list of subsets in the table on the Data Subset Definitions page.

Creating a Subset Version of a Target Database

After a subset is defined, analyzed, and validated, you can execute the subset operation to create a subset version of the source data.

The procedure assumes the following prerequisites:

- A subset definition already exists that contains the rules needed to subset the database.

- You have the requisite privileges to extract the data from the source and create the subset version in a target database. Depending on the subset technique, different levels of file or database privileges may be created. The required privileges include:

- EM_ALL_OPERATOR for Enterprise Manager Cloud Control users

- SELECT_CATALOG_ROLE for database users

- SELECT ANY DICTIONARY privilege for database users

- DBA privileges on a database for target database users

- Additionally, to perform an in-place delete operation, the DBA user must be granted the EXECUTE_ANY_TYPE privilege

To create a subset version of a target database:

1. Create a subset operation by selecting a subset definition and associating it with a source database.
Enterprise Manager validates the subset definition against the source database and flags schema differences. Note that this association may be different from the original association that an application developer may have created.

2. Edit the definition to remap the defined schema to a test schema.
You are prompted to connect to a database, whereupon the database is associated with the subset definition. This also enables you to remap the vendor-provided schema names to actual schema names in the database.

3. Select one of the various subset creation techniques:

- Data Pump dump file followed by a Data Pump import

- In-place delete, in which rows in the specified database not matching the rule conditions are deleted

- In-transit subset creation or refresh

Enterprise Manager generates the appropriate response file (that is, SQL script, Data Pump script, or OS script), checks the target system for appropriate privileges to be able proceed with the operation, and estimates the size of the target.

4. After reviewing the analysis, submit the subset process.
Enterprise Manager executes the subset process and summarizes the results of the execution.

Synchronizing a Subset Definition with an Application Data Model

Changes to an ADM, adding referential relationships or deleting tables, for example, can render a subset definition stale. The Subset Definitions page clearly indicates this condition with a lock icon next to the subset name and an invalid status. Also, most menu items on the Actions menu are disabled. To revert the status to valid and unlock the subset definition, you have to synchronize the definition with its associated ADM.

1. On the Subset Definitions page, select the locked subset definition.

2. From the Actions menu, select Synchronize.

3. Complete the job submission dialog, then click Submit.

When the job completes, the subset definition is unlocked and available for use.

Granting Privileges on a Subset Definition

You can grant privileges on a subset definition that you create so that others can have access. To do so, you must be an Enterprise Manager Administrator with at least Designer privileges on the subset definition.

1. From the Enterprise menu, select Quality Management, then select Data Subset Definitions.

2. Select the subset definition to which you want to grant privileges.

3. From the Actions menu, select Grant, then select as follows:

- Operator–to grant Operator privileges on the subset definition to selected roles or administrators, which means the grantees can view and copy but not edit the definition.

- Designer–to grant Designer privileges on the subset definition to selected roles or administrators, which means the grantees can view and edit the definition.

4. In the dialog that opens, select the type (administrator or role, or both). Search by name, if desired. Make your selections and click Select.

Those selected now have privileges on the subset definition.

5. Use the Revoke action if you want to deny privileges previously granted.

See "Test Data Management and Access Rights" for more information on privileges within the test data management area.

About Inline Masking and Subsetting

You can reduce the size of the database simultaneous with masking sensitive data. This serves the dual purpose of obscuring exported production data while greatly reducing hardware costs related to storing large masked production databases for testing.

Note:

Inline masking is available only with Oracle Database 11g and higher releases.

The benefits of integrating data masking with subsetting include the following:

- Prepare the test system in a single flow

- Avoid the necessity of maintaining large-size masked databases for test purposes

- Exported data in the form of a dump file can be imported into multiple databases without exposing sensitive data

- Subsetting is enhanced by ability to discard columns containing chunks of large data

You can select one or more data masking definitions during subset creation. The masking definitions must be based on the same ADM as the current subset definition. At the same time, you can significantly reduce the subset size by defining column rules to set CLOB and BLOB columns to null (or another supported format such as Fixed String, Fixed Number).

You generate a subset in two ways:

- Export Dump–if masking definitions are part of the subset model, mapping tables are created during generation, and the resulting dump contains masked values

- In-Place Delete–subsetting is performed on a cloned copy of the production database; if data masking is part of the subset model, pregenerated masking scripts are executed on the target sequentially

Advantages of inline masking include the following:

- Sensitive data never leaves the production environment and thus is not exposed (Export Dump option).

- There is no need to temporarily store data in a staging area.

- Exported data can subsequently be imported into multiple environments.

- You can define table rules to export only a subset of data, and can further trim the volume by using column rules to eliminate large vertical columns.

- You can mask the same data in different ways and import into different test databases.

- You can use the provisioning framework to create multiple copies of trimmed down, referentially intact databases containing no sensitive data (in-place delete), or import a dump file into multiple databases (export dump).

The section "Creating a Data Subset Definition" includes instructions for combining data subsetting and data masking within the process of creating a subset definition. See Masking Sensitive Data,for information on data masking and creating a data masking definition.

Inline Masking and Subsetting Scenarios

The scenarios described below assume that an Application Data Model (ADM) exists for a production (or test) database in which sensitive column details are captured. The steps outlined are at a high level. See "Masking with an Application Data Model and Workloads" for details on creating a masking definition; see "Creating a Data Subset Definition" for details on creating and editing a subset definition.

Consider the following scenarios:

- Mask and Export Production Data

- Mask and Delete Operation on a Test Database

- Mask Sensitive Data and Export a Subset of a Production Database

- Perform Subset, Mask, and Delete Operations on a Test Database

- Apply Column Rules

- Export a Subset Definition That Uses Inline Masking

- Import a Subset Definition That Uses Inline Masking

- Import a Subset Dump

- Save Subset Script Bundle

Mask and Export Production Data

As the Security Administrator, you want to create copies of the production database by exporting the data with masked values; that is, the export dump will have only masked values and no sensitive data.

1. Create a masking definition. Implies the following:

a. Select an appropriate ADM.

b. Search and select sensitive columns (includes dependent columns and recommended masking formats).

c. Review suggested formats and edit as necessary.

d. Save the results.

2. Create a subset definition. Implies the following:

a. Select an appropriate ADM.

b. Submit the create subset job.

3. Edit the subset definition.
On the Data Masking tab, search for and select masking definitions. System validation checks for overlapping columns that use multiple masking definitions.

4. Generate the subset using the Export option.

Summarizing the outcome:

- Generates and executes a script to create a mapping table and a mapping function. Also creates a table to map the column(s) to the respective mapping function.

- Copies subsetting and masking scripts to the target database.

- Generates an export dump of production data, replacing sensitive data with masked values using the mapping function.

Mask and Delete Operation on a Test Database

As the Security Administrator, you want to create a usable test database by masking sensitive information. The resulting database will have only masked values and no sensitive data.

1. Create a masking definition on a cloned database. Implies the following:

a. Select an appropriate ADM.

b. Search and select sensitive columns (includes dependent columns and recommended masking formats).

c. Review suggested formats and edit as necessary.

d. Save.

2. Create a subset definition. Implies the following:

a. Select an appropriate ADM.

b. Submit the create subset job.

3. Edit the subset definition.
On the Data Masking tab, search and select masking definitions. System validation checks for overlapping columns that use multiple masking definitions.

4. Generate the subset using the In-Place Delete option.

Summarizing the outcome:

- Copies subsetting and masking scripts to the target database.

- Performs data subsetting based on subset rules, if specified.

- Sequentially executes the pregenerated data masking scripts on the target database.

- Creates a masked copy of the production database for use in testing.

Mask Sensitive Data and Export a Subset of a Production Database

As the Security Administrator, you want to create copies of the production database by exporting a subset of production data with masked values.

1. Create a masking definition. Implies the following:

a. Select an appropriate ADM.

b. Search and select sensitive columns (includes dependent columns and recommended masking formats).

c. Review suggested formats and edit as necessary.

d. Save.

2. Create a subset definition. Implies the following:

a. Select an appropriate ADM.

b. Submit the create subset job.

3. Edit the subset definition.

a. Define table rules, resulting in space estimates.

b. On the Data Masking tab, search and select masking definitions. System validation checks for overlapping columns that use multiple masking definitions.

4. Generate the subset using the Export option.

Summarizing the outcome:

- Generates and executes a script to create a mapping table and a mapping function. Also creates a table to map the column(s) to the respective mapping function.

- Copies subsetting and masking scripts to the target database.

- Generates an export dump of production data, replacing sensitive data with masked values using the mapping function.

Perform Subset, Mask, and Delete Operations on a Test Database

As the Security Administrator, you want to create a usable test database by masking sensitive information. On import, the database will have only masked values and no sensitive data.

1. Create a masking definition. Implies the following:

a. Select an appropriate ADM.

b. Search and select sensitive columns (includes dependent columns and recommended masking formats).

c. Review suggested formats and edit as necessary.

d. Save.

2. Create a subset definition. Implies the following:

a. Select an appropriate ADM.

b. Submit the create subset job.

3. Edit the subset definition.

a. Define table rules, resulting in space estimates.

b. On the Data Masking tab, search and select masking definitions. System validation checks for overlapping columns that use multiple masking definitions.

4. Generate the subset using the In-Place Delete option.

Summarizing the outcome:

- Copies subsetting and masking scripts to the target database.

- Performs data subsetting based on subset rules, if specified.

- Following subset completion, sequentially executes the pregenerated data masking scripts on the target database.

- Applies masking definitions and subsetting rules, resulting in a masked database of reduced size.

Apply Column Rules

As the Security Administrator, you want to create a targeted subset by selecting large-sized columns and setting them to null or a fixed value. Table rules can also be used to further reduce database size. Impact of size reduction is immediately visible and applied to the final subset.

1. Create a subset definition. Implies the following:

a. Select an appropriate ADM.

b. Submit the create subset job.

2. Edit the subset definition.

a. Click the Table Rules tab and select from existing options, if desired.

b. Click the Column Rules tab, then click Create.

c. Specify filtering criteria to search for large-sized columns and select the desired columns in the results table.

d. Click Manage Masking Formats and select a format from the drop-down list. Enter a value if appropriate to the selection.

e. Click OK and review the updated space estimates.

3. Generate the subset, using either the Export or In-Place Delete option.

Summarizing the outcome:

- Generates an export dump/subset of production data.

- Column rules are applied on the target database.

- If table rules were also applied, the resulting subset reflects the combined effect of table and column rules.

Export a Subset Definition That Uses Inline Masking

As the Security Administrator, you want to export a subset definition for reuse.

1. Create a subset definition. Implies the following:

a. Select an appropriate ADM.

b. Submit the create subset job.

2. Edit the subset definition.

a. Create rules to compute space estimates.

b. On the Data Masking tab, search and select masking definitions. System validation checks for overlapping columns that use multiple masking definitions.

3. Select the subset definition on the Subset home page and export it.

The subset definition is saved on the client machine as an XML file that potentially contains the following:

- Information on selected applications

- Rules and rule parameters

- Selected masking definitions

- Columns to set to null

- Pre- and post-scripts

Had column rules been used, they would replace the masking definitions in the list.

Import a Subset Definition That Uses Inline Masking

As the Security Administrator, you want to import a subset definition XML file to create replicas of the subset definition previously exported.

1. Import a subset definition.

2. Select an exported XML template that contains exported masking definitions. System validation:

- Checks for overlapping columns that use multiple masking definitions.

- Ensures that the masking definition specified is part of the same ADM as the current subset model.

3. Submit the job to create the subset model.

Summarizing the outcome:

- Creates a subset definition model

- Applies specified rules and calculates space estimates

- Remembers masking definitions that were part of the XML

Import a Subset Dump

As the Security Administrator, you want to import a subset dump, which might contain either or both of the following:

- A masked version of a production database

- A subset version of a production database

Note that this example assumes a previous export dump.

1. On the subset home page, select Import Subset Dump from the Actions menu.

2. Provide credentials, a dump name, and select the dump location.

3. Provide the import type, tablespace options, and log file location details.

4. Schedule the job and submit.

The job reads the dump files and loads the data into the selected target database.

Save Subset Script Bundle

As the Security Administrator, you want to save a subset script bundle so that it can be executed on a target database external to Enterprise Manager.

This example presupposes the existence of a subset model that has required table rules and masking definitions.

1. On the subset home page, from the Actions menu, select Generate, then select Subset.

2. Complete the mode page as follows:

a. Indicate the method of subset creation.

b. Specify which credentials to use.

c. Provide rule parameters as appropriate.

d. Click Continue.

3. Complete the parameters page as follows:

a. Select the location where to save the subset export.

b. If the subset is to be stored externally, click the check box and select the location.

c. Specify an export file name. Note that you can use the % wildcard.

d. Specify the maximum file size and number of threads.

e. Indicate whether to generate a log file and specify a log file name.

f. Click Continue.

4. Note the progress of the script file generation. When complete, click Download.

5. Specify where to save the SubsetBundle.zip file.

19 Masking Sensitive Data

This chapter provides conceptual information about the components that comprise Oracle Data Masking, and procedural information about performing the task sequence, such as creating masking formats and masking definitions. Data masking presupposes that you have created an Application Data Model (ADM) with defined sensitive columns.

Topics discussed in this chapter include:

- Overview of Oracle Data Masking

- Format Libraries and Masking Definitions

- Recommended Data Masking Workflow

- Data Masking Task Sequence

- Defining Masking Formats

- Masking with an Application Data Model and Workloads

- Masking a Test System to Evaluate Performance

- Upgrade Considerations

- Using the Shuffle Format

- Using Group Shuffle

- Using Conditional Masking

- Using Data Masking with LONG Columns

The procedures in this chapter are applicable to Oracle Enterprise Manager 12.1 and higher Cloud Control only. You must have the Oracle Data Masking and Subsetting Pack license to use data masking features.

Note:

Performing masking on an 11.2.0.3 database that uses Database Plug-in 12.1.0.3 or higher requires that database patch # 16922826 be applied for masking to run successfully.

Overview of Oracle Data Masking

Enterprises run the risk of breaching sensitive information when copying production data into non-production environments for the purposes of application development, testing, or data analysis. Oracle Data Masking helps reduce this risk by irreversibly replacing the original sensitive data with fictitious data so that production data can be shared safely with non-production users. Accessible through Oracle Enterprise Manager, Oracle Data Masking provides end-to-end secure automation for provisioning test databases from production in compliance with regulations.

Data Masking Concepts

Data masking (also known as data scrambling and data anonymization) is the process of replacing sensitive information copied from production databases to test non-production databases with realistic, but scrubbed, data based on masking rules. Data masking is ideal for virtually any situation when confidential or regulated data needs to be shared with non-production users. These users may include internal users such as application developers, or external business partners such as offshore testing companies, suppliers and customers. These non-production users need to access some of the original data, but do not need to see every column of every table, especially when the information is protected by government regulations.

Data masking enables organizations to generate realistic and fully functional data with similar characteristics as the original data to replace sensitive or confidential information. This contrasts with encryption or Virtual Private Database, which simply hides data, and the original data can be retrieved with the appropriate access or key. With data masking, the original sensitive data cannot be retrieved or accessed.

Names, addresses, phone numbers, and credit card details are examples of data that require protection of the information content from inappropriate visibility. Live production database environments contain valuable and confidential data—access to this information is tightly controlled. However, each production system usually has replicated development copies, and the controls on such test environments are less stringent. This greatly increases the risks that the data might be used inappropriately. Data masking can modify sensitive database records so that they remain usable, but do not contain confidential or personally identifiable information. Yet, the masked test data resembles the original in appearance to ensure the integrity of the application.

Security and Regulatory Compliance

Masked data is a sensible precaution from a business security standpoint, because masked test information can help prevent accidental data escapes. In many cases, masked data is a legal obligation. The Enterprise Manager Data Masking Pack can help organizations fulfill legal obligations and comply with global regulatory requirements, such as Sarbanes-Oxley, the California Database Security Breach Notification Act (CA Senate Bill 1386), and the European Union Data Protection Directive.

The legal requirements vary from country to country, but most countries now have regulations of some form to protect the confidentiality and integrity of personal consumer information. For example, in the United States, The Right to Financial Privacy Act of 1978 creates statutory Fourth Amendment protection for financial records, and a host of individual state laws require this. Similarly, the U.S. Health Insurance Portability and Accountability Act (HIPAA) created protection of personal medical information.

Roles of Data Masking Users

The following types of users participate in the data masking process for a typical enterprise:

- Application database administrator or application developer
This user is knowledgeable about the application and database objects. This user may add additional custom database objects or extensions to packaged applications, such as the Oracle E-Business suite.

- Information security administrator
This user defines information security policies, enforces security best practices, and also recommends the data to be hidden and protected.

Related Oracle Security Offerings

Besides data masking, Oracle offers the following security products:

- Virtual Private Database or Oracle Label Security — Hides rows and data depending on user access grants.

- Transparent Data Encryption — Hides information stored on disk using encryption. Clients see unencrypted information.

- DBMS_CRYPTO — Provides server packages that enable you to encrypt user data.

- Database Vault — Provides greater access controls on data.

Agent Compatibility for Data Masking

Data masking supports Oracle Database 9i and newer releases. If you have a version prior to 11.1, you can use it by implementing the following workaround.

Replace the following file...

AGENT_HOME/sysman/admin/scripts/db/reorg/reorganize.pl

... with this file:

OMS_HOME/sysman/admin/scripts/db/reorg/reorganize.pl

Supported Data Types

The list of supported data types varies by release.

- Grid Control 10g Release 5 (10.2.0.5), Database 11g Release 2 (11.2), and Cloud Control 12c Release 1 (12.1.0.1) and Release 2 (12.1.0.2)

- Numeric Types
The following Numeric Types can use Array List, Delete, Fixed Number, Null Value, Post Processing Function, Preserve Original Data, Random Decimal Numbers, Random Numbers, Shuffle, SQL Expression, Substitute, Table Column, Truncate, Encrypt, and User Defined Function masking formats:

- NUMBER

- FLOAT

- RAW

- BINARY_FLOAT

- BINARY_DOUBLE

- String Types
The following String Types can use Array List, Delete, Fixed Number, Fixed String, Null Value, Post Processing Function, Preserve Original Data, Random Decimal Numbers, Random Digits, Random Numbers, Random Strings, Shuffle, SQL Expression, Substitute, Substring, Table Column, Truncate, Encrypt, and User Defined Function masking formats:

- CHAR

- NCHAR

- VARCHAR2

- NVARCHAR2

- Date Types
The following Date Types can use Array List, Delete, Null Value, Post Processing Function, Preserve Original Data, Random Dates, Shuffle, SQL Expression, Substitute, Table Column, Truncate, Encrypt, and User Defined Function masking formats:

- DATE

- TIMESTAMP

- Grid Control 11g Release 1 (11.1) and Cloud Control 12c Release 1 (12.1.0.1) and Release 2 (12.1.0.2)

- Large Object (LOB) Data Types
The following Data Types can use Fixed Number, Fixed String, Null Value, and SQL Expression masking formats:

- BLOB

- CLOB

- NCLOB

Format Libraries and Masking Definitions

To mask data, the Data Masking Pack provides two main features:

- Masking format library
The format library contains a collection of ready-to-use masking formats. The library consists of format routines that you can use for masking. A masking format can either be one that you create, or one from the list of Oracle-supplied default masking formats.

As a matter of best practice, organizations should create masking formats for all commonly regulated information so that the formats can be applied to the sensitive data regardless of which database the sensitive data resides in. This ensures that all sensitive data is consistently masked across the entire organization.

- Masking definitions
A masking definition defines a data masking operation to be implemented on one or more tables in a database. Masking definitions associate table columns with formats to use for masking the data. They also maintain the relationship between columns that are not formally declared in the database using related columns.

You can create a new masking definition or use an existing definition for a masking operation. To create a masking definition, you specify the column of the table for which the data should be masked and the format of masked data. If the columns being masked are involved in unique, primary key, or foreign key constraints, data masking generates the values so that the constraints are not violated. Masking ensures uniqueness per character using decimal arithmetic. For example, a 5-character string generates a maximum of only 99999 unique values. Similarly, a 1-character string generates a maximum of only 9 unique values.

You would typically export masking definitions to files and import them on other systems. This is important when the test and production sites reside on different Oracle Management Systems or on entirely different sites.

See Also:

The online help topic "Creating a Data Masking Definition" as well as the help for each Data Masking page

Recommended Data Masking Workflow

Figure 19-1 shows that the production database is cloned to a staging region and then masked there. During the masking process, the staging and test areas are tightly controlled like a production site.

Figure 19-1 Data Masking Workflow

Data masking is an iterative and evolving process handled by the security administrator and implemented by the database administrator. When you first configure data masking, try out the masking definition on a test system, then add a greater number of columns to the masking definition and test it to make sure it functions correctly and does not break any application constraints. During this process, you should exercise care when removing all imbedded references to the real data while maintaining referential integrity.

After data masking is configured to your satisfaction, you can use the existing definition to repeatedly mask after cloning. The masking definition, however, would need to evolve as new schema changes require new data and columns to be masked.

After the masking process is complete, you can distribute the database for wide availability. If you need to ship the database to another third-party site, you are required to use the Data Pump Export utility, and then ship the dump file to the remote site. However, if you are retaining the masked data in-house, see "Data Masking Task Sequence".

You can also perform inline, or at the source, data masking while creating a subset definition. See "Creating a Data Subset Definition" for more information.

Data Masking Task Sequence

The task sequence in this section demonstrates the data masking workflow and refers you to additional information about some of the tasks in the sequence. Before reviewing this sequence, note that there are two options for completing this process:

- Exporting/importing to another database
You can clone the production database to a staging area, mask it, then export/ import it to another database before delivering it to in-house testers or external customers. This is the most secure approach.

- Making the staging area the new test region
You can clone the production database to a mask staging area, then make the staging area the new test region. In this case, you should not grant testers SYSDBA access or access to the database files. Doing so would compromise security. The masked database contains the original data in unused blocks and in the free list. You can only purge this information by exporting/importing the data to another database.

The following basic steps guide you through the data masking process, with references to other sections for supporting information.

1. Review the application database and identify the sources of sensitive information.

2. Define mask formats for the sensitive data. The mask formats may be simple or complex depending on the information security needs of the organization.

For more information, see "Creating New Masking Formats" and "Using Oracle-supplied Predefined Masking Formats".

3. Create a masking definition to associate table columns to these mask formats. Data masking determines the database foreign key relationships and adds foreign key columns to the mask.

For more information, see "Masking with an Application Data Model and Workloads" .

4. Save the masking definition and generate the masking script.

5. Verify if the masked data meets the information security requirements. Otherwise, refine the masking definition, restore the altered tables, and reapply the masking definition until the optimal set of masking definitions has been identified.

6. Clone the production database to a staging area, selecting the masking definition to be used after cloning. Note that you can clone using Enterprise Manager, which enables you to add masking to the Enterprise Manager clone workflow. However, if you clone outside of Enterprise Manager, you must initiate masking from Enterprise Manager after cloning is complete. The cloned database should be controlled with the same privileges as the production system, because it still contains sensitive production data.

After cloning, be sure to change the passwords as well as update or disable any database links, streams, or references to external data sources. Back up the cloned database, or minimally the tables that contain masked data. This can help you restore the original data if the masking definition needs to be refined further.

For more information, see "Cloning the Production Database" .

7. After masking, test all of your applications, reports, and business processes to ensure they are functional. If everything is working, you can export the masking definition to keep it as a back-up.

8. After masking the staging site, make sure to drop any tables named MGMT_DM_TT before cloning to a test region. These temporary tables contain a mapping between the original sensitive column value and the mask values, and are therefore sensitive in nature.

During masking, Enterprise Manager automatically drops these temporary tables for you with the default "Drop temporary tables created during masking" option. However, you can preserve these temporary tables by deselecting this option. In this case, you are responsible for deleting the temporary tables before cloning to the test region.

9. After masking is complete, ensure that all tables loaded for use by the substitute column format or table column format are going to be dropped. These tables contain the mask values that table column or substitute formats will use. It is recommended that you purge this information for security reasons.

For more information, see "Deterministic Masking Using the Substitute Format" .

10. Clone the database to a test region, or use it as the new test region. When cloning the database to an external or unsecured site, you should use Export or Import. Only supply the data in the database, rather than the database files themselves.

11. As part of cloning production for testing, provide the masking definition to the application database administrator to use in masking the database.

Defining Masking Formats

A masking definition requires one or more masking formats for any columns included in the masking definition. When adding columns to a masking definition, you can either create masking formats manually or import them from the format library. It is often more efficient to work with masking formats from the format library.

Creating New Masking Formats

This section describes how to create new masking formats using Enterprise Manager.

To create a masking format in the format library:

1. From the Enterprise menu, select Quality Management, then Data Masking Formats. Alternatively, if you are in the Database home page, select Data Masking Format Library from the Schema menu.
The Format Library appears with predefined formats that Oracle Enterprise Manager provides.

2. Click Create.
The Create Format page appears, where you can define a masking format.

See Also:

The online help for information on page user controls

3. Provide a required name for the new format, select a format entry type from the Add list, then click Go.
A page appears that enables you to provide input for the format entry you have selected. For instance, if you select Array List, the subsequent page enables you to enter a list of values, such as New York, New Jersey, and New Hampshire.

4. Continue adding additional format entries as needed.

5. When done, provide an optional user-defined or post-processing function (see "Providing User-defined and Post-processing Functions"), then click OK to save the masking format.
The Format Library page reappears with your newly created format displayed in the Format Library table. You can use this format later to mask a column of the same sensitive type.

See Also:

The online help for information on the Format Library and Create Format pages

Providing User-defined and Post-processing Functions

If desired, you can provide user-defined and post-processing functions on the Create Format page. A user-defined choice is available in the Add list, and a post-processing function field is available at the bottom of the page.

- User-defined functions
To provide a user-defined function, select User Defined Function from the Add list, then click Go to access the input fields.

A user-defined function passes in the original value as input, and returns a mask value. The data type and uniqueness of the output values must be compatible with the original output values. Otherwise, a failure occurs when the job runs. Combinable, a user-defined function is a PL/SQL function that can be invoked in a SELECT statement. Its signature is returned as:

Function udf_func (rowid varchar2, column_name varchar2, original_value varchar2) returns varchar2;

- rowid is the min (rowid) of the rows that contain the value original_value 3rd argument.

- column_name is the name of the column being masked.

- original_value is the value being masked.

That is, it accepts the original value as an input string, and returns the mask value.

Both input and output values are varchar2. For instance, a user-defined function to mask a number could receive 100 as input, the string representation of the number 100, and return 99, the string representation of the number 99. Values are cast appropriately when inserting to the table. If the value is not castable, masking fails.

- Post-processing functions
To provide a post-processing function, enter it in the Post Processing Function field.

A post-processing function has the same signature as a user-defined function, but passes in the mask value the masking engine generates, and returns the mask value that should be used for masking, as shown in the following example:

Function post_proc_udf_func (rowid varchar2, column_name varchar2, mask_value varchar2) returns varchar2;

- rowid is the min (rowid) of the rows that contain the value mask_value.

- column_name is the name of the column being masked.

- mask_value is the value being masked.

Using Masking Format Templates

After you have created at least one format, you can use the format definition as a template in the Create Format page, where you can implement most of the format using a different name and changing the entries as needed, rather than needing to create a new format from scratch.

To create a new format similar to an existing format, select a format on the Format Library page and click Create Like. The masking format you select can either be one you have previously defined yourself, or one from the list of out-of-box masking formats. You can use these generic masking format definitions for different applications.

For instructional details about the various Oracle-supplied predefined masking format definitions and how to modify them to suit your needs, see "Using Oracle-supplied Predefined Masking Formats".

Using Oracle-supplied Predefined Masking Formats

Enterprise Manager provides several out-of-box predefined formats. All predefined formats and built-in formats are random. The following sections discuss the various Oracle-supplied format definitions and how to modify them to suit your needs:

- Patterns of Format Definitions

- Category Definitions

See Also:

"Installing the DM_FMTLIB Package" for information on installing the DM_FMTLIB package so that you can use the predefined masking formats

Patterns of Format Definitions

All of the format definitions adhere to these typical patterns:

- Generate a random number or random digits.

- Perform post-processing on the above-generated value to ensure that the final result is a valid, realistic value.

For example, a valid credit card number must pass Luhn's check. That is, the last digit of any credit card number is a checksum digit, which is always computed. Also, the first few digits indicate the card type (MasterCard, Amex, Visa, and so forth). Consequently, the format definition of a credit card would be as follows:

- Generate random and unique 10-digit numbers.

- Using a post-processing function, transform the values above to a proper credit card number by adding well known card type prefixes and computing the last digit.

This format is capable of generating 10 billion unique credit card numbers.

Category Definitions

The following sections discuss different categories of these definitions:

- Credit Card Numbers

- United States Social Security Numbers

- ISBN Numbers

- UPC Numbers

- Canadian Social Insurance Numbers

- North American Phone Numbers

- UK National Insurance Numbers

- Auto Mask

By default, these mask formats are also available in different format styles, such as a hyphen ( - ) format. If needed, you can modify the format style.

Credit Card Numbers

Out of the box, the format library provides many different formats for credit cards. The credit card numbers generated by these formats pass the standard credit card validation tests by the applications, thereby making them appear like valid credit card numbers.

Some of the credit card formats you can use include:

- MasterCard numbers

- Visa card numbers

- American Express card numbers

- Discover Card numbers

- Any credit card number (credit card numbers belong to all types of cards)

You may want to use different styles for storing credit card numbers, such as:

- Pure numbers

- 'Space' for every four digits

- 'Hyphen' ( - ) for every four digits, and so forth

To implement the masked values in a certain format style, you can set the DM_CC_FORMAT variable of the DM_FMTLIB package. To install the package, see "Installing the DM_FMTLIB Package" .

United States Social Security Numbers

Out of the box, you can generate valid U.S. Social Security (SSN) numbers. These SSNs pass the normal application tests of a valid SSN.

You can affect the format style by setting the DM_SSN_FORMAT variable of the DM_FMTLIB package. For example, if you set this variable to ‘-', the typical social security number would appear as ‘123-45-6789'.

ISBN Numbers

Using the format library, you can generate either 10-digit or 13-digit ISBN numbers. These numbers adhere to standard ISBN number validation tests. All of these ISBN numbers are random in nature. Similar to other format definitions, you can affect the "style" of the ISBN format by setting values to DM_ISBN_FORMAT.

UPC Numbers

Using the format library, you can generate valid UPC numbers. They adhere to standard tests for valid UPC numbers. You can affect the formatting style by setting the DM_UPC_FORMAT value of the DM_FMTLIB package.

Canadian Social Insurance Numbers

Using the format library, you can generate valid Canadian Social Insurance Numbers (SINs). These numbers adhere to standard tests of Canadian SINs. You can affect the formatting style by setting the DM_CN_SIN_FORMAT value of the DM_FMTLIB package.

North American Phone Numbers

Out of the box, the format library provides various possible U.S. and Canadian phone numbers. These are valid, realistic looking numbers that can pass standard phone number validation tests employed by applications. You can generate the following types of numbers:

- Any North American phone numbers

- Any Canadian phone number

- Any U.S.A. phone number

UK National Insurance Numbers

Using the format library, you can generate valid unique random UK National Insurance Numbers (NINs). These numbers adhere to standard tests of UK NINs. A typical national insurance number would appear as 'GR 12 56 34 RS'.

Auto Mask

This format scrambles characters and numbers into masked characters and numbers and while retaining the format and length of the data, including special characters; for example, 'ABCD_343-ddg' masked as 'FHDT_657-tte'.

Installing the DM_FMTLIB Package

The predefined masking formats use functions defined in the DM_FMTLIB package. This package is automatically installed in the DBSNMP schema of your Enterprise Manager repository database. To use the predefined masking formats on a target database (other than the repository database), you must manually install the DM_FMTLIB package on that database.

To install the DM_FMTLIB package:

1. Locate the following scripts in your Enterprise Manager installation:

$PLUGIN_HOME/sql/db/latest/masking/dm_fmtlib_pkgdef.sql
$PLUGIN_HOME/sql/db/latest/masking/dm_fmtlib_pkgbody.sql

Where PLUGIN_HOME can be any of the locations returned by the following SQL SELECT statement, executed as SYSMAN:

select PLUGIN_HOME from gc_current_deployed_plugin where plugin_id='oracle.sysman.db' and destination_type='OMS';

2. Copy these scripts to a directory in your target database installation and execute them using SQL*Plus, connected as a user that can create packages in the DBSNMP schema.
You can now use the predefined masking formats in your masking definitions.

3. Select and import any predefined masking format into a masking definition by clicking the Import Format button on the Define Column Mask page.

Providing a Masking Format to Define a Column

When you create a masking definition ("Masking with an Application Data Model and Workloads"), you will be either importing a format or selecting one from the available types in the Define Column Mask page. Format entry options are as follows:

- Array List
The data type of each value in the list must be compatible with that of the masked column. Uniqueness must be guaranteed if needed. For example, for a unique key column that already has 10 distinct values, the array list should also contain at least 10 distinct values.

- Delete
Deletes the specified rows as identified by the condition clauses. If a column includes a delete format for one of its conditions, a foreign key constraint or a dependent column cannot refer to the table.

- Encrypt
Encrypts column data by specifying a regular expression. The column values in all the rows must match the regular expression. This format can be used to mask data consistently across databases. That is, for a given value it always generates the same masked value.

For example, the regular expression [(][1-9][0-9]{2}[)][_][0-9]{3}[-][0-9]{4} generates U.S. phone numbers such as (123) 456-7890.

This format supports a subset of the regular expression language. It supports encrypting strings of fixed widths. However, it does not support * or + syntax of regular expressions.

If a value does not match the format specified, the encrypted value may no longer produce one-to-one mappings. All non-confirming values are mapped to a single encrypted value, thereby producing a many-to-one mapping.

- Fixed Number
The type of column applicable to this entry is a NUMBER column or a STRING column. For example, if you mask a column that has a social security number, one of the entries can be Fixed Number 900. This format is combinable.

- Fixed String
The type of column applicable to this entry is a STRING column. For example, if you mask a column that has a License Plate Number, one of the entries can be Fixed String CA. This format is combinable.

- Null Value
Masks the column using a value of NULL. The column must be nullable.

- Post-Processing Function
This is a special function that you can apply to the mask value that the masking engine generates. This function takes the mask value as input and returns the actual mask value to be used for masking.

The post-processing function is called after the mask value is generated. You can use it, for instance, to add commas or dollar signs to a value. For example, if a mask value is a number such as 12000, the post processing function can modify this to $12,000. Another use is for adding checksums or special encodings for the mask value that is produced.

In the following statement:

Function post_proc_udf_func (rowid varchar2, column_name varchar2, mask_value varchar2) returns varchar2;

- rowid is the min (rowid) of the rows that contains the value mask_value 3rd argument.

- column_name is the name of the column being masked.

- mask_value is the value being masked.

- Preserve Original Data
Retains the original values for rows that match the specified condition clause. This is used in cases where some rows that match a condition do not need to be masked.

- Random Dates
The uniqueness of the Date column is not maintained after masking. This format is combinable.

- Random Decimal Numbers
If used as part of a mixed random string, these have limited usage for generating unique values. This masking format generates unique values within the specified range. For example, a starting value of 5.5 and ending value of 9.99 generates a decimal number ranging from 5.5 to 9.99, both inclusive. This masking format is combinable.

- Random Digits
This format generates unique values within the specified range. For example, for a random digit with a length of [5,5], an integer between [0, 99999] is randomly generated, left padded with '0's to satisfy the length and uniqueness requirement. This is a complementary type of random number, which will not be padded. When using random digits, the random digit pads to the appropriate length in a string. It does not pad when used for a number column. This format is combinable.

Data masking ensures that the generated values are unique, but if you do not specify enough digits, you could run out of unique values in that range.

- Random Numbers
If used as part of a mixed random string, these have limited usage for generating unique values. This format generates unique values within the specified range. For example, a starting value of 100 and ending value of 200 generates an integer number ranging from 100 to 200, both inclusive. Note that Oracle Enterprise Manager release 10.2.0.4.0 does not support float numbers. This format is combinable.

- Random Strings
This format generates unique values within the specified range. For example, a starting length of 2 and ending length of 6 generates a random string of 2 - 6 characters in length. This format is combinable.

- Regular Expression
This format enables you to use regular expressions to search for sensitive data in LOBs (BLOB, CLOB, NCLOB) and replace the data with a fixed string, a fixed number, null, or SQL Expression. Use rules to search for multiple strings within a LOB.

Examples:

- Use the regular expression [0-9]{3}[.][0-9]{3}[.][0-9]{4} to match strings of the format nnn.nnn.nnnn and replace with a masked value, for example, ***.***.****

- Use the regular expression <SALARY>[0-9]{2,6}</SALARY> to zero out salary information by replacing with <SALARY>0</SALARY>

- Use the regular expression [A-Z]+@[A-Z]+\.[A-Z]{2,4} to mask e-mail addresses by replacing with john.doe@acme.com

You can also use this format with data type VARCHAR2 to mask part of a string.

- Shuffle
This format randomly shuffles the original column data. It maintains data distribution except when a column is conditionally masked and its values are not unique.

For more information, see "Using the Shuffle Format".

- Substitute
This format uses a hash-based substitution for the original value and always yields the same mask value for any given input value. Specify the substitution masking table and column. This format has the following properties:

- The masked data is not reversible. That is, this format is not vulnerable to external security breaches because the original value is replaced, so it is not possible to retrieve the original value from the mask value.

- Masking multiple times with a hash substitute across different databases yields the same mask value. This characteristic is valid across multiple databases or multiple runs assuming that the same substitution values are used in the two runs. That is, the actual rows and values in the substitution table do not change. For example, suppose the two values Joe and Tom were masked to Henry and Peter. When you repeat the same mask on another database using the same substitution table, if there were Bob and Tom, they might be replaced with Louise and Peter. Notice that even though the two runs have different data, Tom is always replaced with Peter.

- This format does not generate uniqueness.

- SQL Expression
This masking format enables you to enter a SQL Expression for masking a column. Data masking uses this expression to generate masked values to replace the original values. You cannot combine a column using this masking format type with other masking format types, such as Random Numbers or Random Strings.

The SQL Expression can consist of one or more values, operators, and SQL functions that evaluates to a value. It can also contain substitution columns (columns from the same table as the masked column). You should specify substitution columns within percent signs (%). Use SQL Expressions with dbms_lob and other user-defined functions for LOB (BLOB, CLOB, NCLOB) masking.

Examples:

- dbms_random.string('u', 8) || '@company.com'
Generates random e-mail addresses.

- %first_name% || '.' || %last_name% || '@company.com'
Generates e-mail addresses using first_name and last_name column values. In this example, first_name and last_name are the substitution columns.

- CLOB Masking
dbms_lob.empty_clob()

Empties the CLOB.

custom_mask_clob(%CLOB_COL%)

Applies the custom mask function to the clob column CLOB_COL.

- Conditional Mask
(case when %PARTY_TYPE%='PERSON' then %PERSON_FIRST_NAME%|| ' ' ||%PERSON_LAST_NAME% else (select dbms_random.string('U', 10) from dual) end)

Columns within %% are present in the same table. The expression masks PERSON_FULL_NAME with the first and last name; otherwise, the mask is a random string.

- Substitution Mask
select MASK_ZIPCODE from data_mask.DATA_MASK_ADDR where ADDR_SEQ = ora_hash( %ZIPCODE% , 1000, 1234)

Select 1000 rows in the substitution table data_mask.DATA_MASK_ADDR. Mask %ZIPCODE% with the MASK_ZIPCODE column in the substitution table. The row selected is dependent on ora_hash and is deterministic in this case. Selection is random if dbms_random procedures are used.

- Substitute
This format uses a hash-based substitution for the original value and always yields the same mask value for any given input value. Specify the substitution masking table and column. This format has the following properties:

- The masked data is not reversible. That is, this format is not vulnerable to external security breaches, because the original value is replaced, so it is not possible to retrieve the original value from the mask value.

- Masking multiple times with a hash substitute across different databases yields the same mask value. This characteristic is valid across multiple databases or multiple runs assuming that the same substitution values are used in the two runs. That is, the actual rows and values in the substitution table do not change. For example, suppose the two values Joe and Tom were masked to Henry and Peter. When you repeat the same mask on another database using the same substitution table, if there were Bob and Tom, they might be replaced with Louise and Peter. Notice that even though the two runs have different data, Tom is always replaced with Peter.

- This format does not guarantee uniqueness.

- Substring
Substring is similar to the database substr function. The start position can be either a positive or a negative integer. For example, if the original string is abcd, a substring with a start position of 2 and length of 3 generates a masked string of bcd. A substring with start position of -2 and length of 3 generates a masked string of cd. This format is combinable.

- Table Column
A table column enables you to select values from the chosen column as the replacement value or part thereof. The data type and uniqueness must be compatible. Otherwise, a failure occurs when the job runs. This format is combinable.

- Truncate
Truncates all rows in a table. If one of the columns in a table is marked as truncated, the entire table is truncated, so no other mask formats can be specified for any of the other columns. If a table is being truncated, it cannot be referred to by a foreign key constraint or a dependent column.

- User Defined Function
The data type and uniqueness of the output values must be compatible with the original output values. Otherwise, a failure occurs when the job runs.

In the following statement:

Function udf_func (rowid varchar2, column_name varchar2, original_value varchar2) returns varchar2;

- rowid is the min (rowid) of the rows that contain the value original_value 3rd argument.

- column_name is the name of the column being masked.

- original_value is the value being masked.

Deterministic Masking Using the Substitute Format

You may occasionally need to consistently mask multiple, distinct databases. For instance, if you run HR, payroll, and benefits that have an employee ID concept on three separate databases, the concept may be consistent for all of these databases, in that an employee's ID can be selected to retrieve the employee's HR, payroll, or benefits information. Based on this premise, if you were to mask the employee's ID because it actually contains his/her social security number, you would have to mask this consistently across all three databases.

Deterministic masking provides a solution for this problem. You can use the Substitute format to mask employee ID column(s) in all three databases. The Substitute format uses a table of values from which to substitute the original value with a mask value. As long as this table of values does not change, the mask is deterministic or consistent across the three databases.

See Also:

The online help for Define Column Mask page for more information on the Substitute format

Masking with an Application Data Model and Workloads

Before creating a masking definition, note the following prerequisites and advisory information:

- Ensure that you have the following minimum privileges for data masking:

- EM_ALL_OPERATOR for Enterprise Manager Cloud Control users

- SELECT_CATALOG_ROLE for database users

- SELECT ANY DICTIONARY privilege for database users

- EXECUTE privileges for the DBMS_CRYPTO package

- Ensure the format you select does not violate check constraints and does not break any applications that use the data.

- For triggers and PL/SQL packages, data masking recompiles the object.

- Exercise caution when masking partitioned tables, especially if you are masking the partition key. In this circumstance, the row may move to another partition.

- Data Masking does not support clustered tables, masking information in object tables, XML tables, and virtual columns. Relational tables are supported for masking.

- If objects are layered on top of a table such as views, materialized views, and PL/SQL packages, they are recompiled to be valid.

If you plan to mask a test system intended for evaluating performance, the following practices are recommended:

- Try to preserve the production statistics and SQL profiles after masking by adding a pre-masking script to export the SQL profiles and statistics to a temporary table, then restoring after masking completes.

- Run a SQL Performance Analyzer evaluation to understand the masking impact on performance. Any performance changes other than what appears in the evaluation report are usually related to application-specific changes on the masked database.

To create a masking definition:

1. From the Enterprise menu, select Quality Management, then Data Masking Definitions.
The Data Masking Definitions page appears, where you can create and schedule new masking definitions and manage existing masking definitions.

2. Click Create to go to the Create Masking Definition page.
A masking definition includes information regarding table columns and the format for each column. You can choose which columns to mask, leaving the remaining columns intact.

3. Provide a required Name, Application Data Model, and Reference Database.
When you click the search icon and select an Application Data Model (ADM) name from the list, the system automatically populates the Reference Database field.

- Optional: Check Ensure Workload Masking Compatibility if you want to mask Capture files and SQL Tuning Sets.
When you enable this check box, the masking definition is evaluated to determine if the SQL Expression format or conditional masking is being used. If either is in use when you click OK, the option becomes unchecked and an error message appears asking you to remove these items before selecting this option.

Note:

Before proceeding to the next step, one or more sensitive columns must already be defined in the Application Data Model. See "Managing Sensitive Column Types" for more information.

4. Click Add to go to the Add Columns page, where you can choose which sensitive columns in the ADM you want to mask. See "Adding Columns for Masking" for information on adding columns.
The results appear in the Columns table. Primary key and foreign key columns appear below the sensitive columns.

5. Use filtering criteria to refine sensitive column results. For example, perhaps you want to isolate all columns that have order in the name (column name=order%). You first may have to expose the filter section (Show Filters).

6. Use the disable feature to exclude certain columns from masking consideration. All columns are enabled by default. You can disable selected or all columns. You can also search for a subset of columns (column name=order%) to disable. The Status column on the right changes to reflect a column's disabled state. Note that a column's disabled state persists on export of a data masking definition.

7. Optional. Click the edit icon in the Format column to review and edit the masking format.

8. Expand Show Advanced Options and decide whether the selected default data masking options are satisfactory.
For more information, see "Selecting Data Masking Advanced Options".

9. Click OK to save your definition and return to the Data Masking Definitions page.
At this point, super administrators can see each other's masking definitions.

10. Select the definition and click Generate Script. The schedule job dialog opens. You may have to log in to the database first. For information on script generation, see "Scheduling a Script Generation Job".
Complete the schedule job dialog by providing the required information, then click Submit.

11. A message appears denoting that the job was submitted successfully and you return to the Data Masking Definitions page, where the status is "Generating Script." Click View Job Details to open the job summary page.
When the job completes, click Log Report to check whether sufficient disk space is available for the operation, and to determine the impact on other destination objects, such as users, after masking. If any tables included in the masking definition have columns of data type LONG, a warning message may appear. For more information, see "Using Data Masking with LONG Columns".

12. When the status on the Data Masking Definitions page is "Script Generated," select the script and choose from the following actions:

- Clone Database–to clone and mask the database using the Clone Database wizard (this requires a Database Lifecycle Management Pack license). For more information, see "Cloning the Production Database".

- Save Script–to save the entire PL/SQL script to your desktop.

- Save Mask Bundle–to download a zip file containing the SQL files generated as part of the At source masking script generation option. You can then extract and execute the script to create a masked dump of the database.

- View Script–to view the PL/SQL script, which you can edit and save. You can also view errors and warnings, if any, in the impact report.

Click Go to execute the selected action.

13. If you are already working with a test database and want to directly mask the data in this database, click Schedule Job. For information on masking a database, see "Scheduling a Data Masking Job".

- Provide the requisite information and desired options. You can specify the database at execution time to any database. The system assumes that the database you select is a clone of the source database. By default, the source database from the ADM is selected.

- Click Submit.
The Data Masking Definitions page appears. The job has been submitted to Enterprise Manager and the masking process appears. The Status column on this page indicates the current stage of the process.

Note that you can also perform data masking at the source as part of a data subsetting definition. See "Creating a Data Subset Definition" for more information.

Editing a Data Masking Definition

Use the following procedure to edit or otherwise work with a masking definition:

1. From the Data Masking Definitions page, click the radio button next to the definition you want to edit, then click Edit.

2. Add columns or edit format entries as you would when creating a new definition, which is explained starting in Step 3 above.

3. Click OK on the Edit Masking Definitions page when you have finished editing.

4. Perform these other actions with an existing masking definition by choosing the respective menu item from the Actions menu:

- Create Like–to display the masking definition in the Create Masking Definition page where you can customize the definition.

- Grant Designer–to grant Designer privileges on the masking definition to selected roles or administrators, which means the grantees can view and edit the definition. Privileges granted can also be revoked.

- Grant Operator–to grant Operator privileges on the masking definition to selected roles or administrators, which means the grantees can view and copy but not edit the definition. Privileges granted can also be revoked.

- Export–to export the definition as an XML file for use in other repositories.

Click Go to execute the selected action.

Adding Columns for Masking

Use this page to add one or more columns for masking and automatically add foreign key columns. Select the database columns you want to mask from the corresponding schema. After you select the columns, you specify the format used to mask the data within.

Note:

You need to add at least one column in the masking definition. Otherwise, you cannot generate a script that creates an impact report that provides information about the objects and resources examined and lists details of any warnings or errors detected.

1. Enter search criteria, then click Search.

The sensitive columns you defined in the ADM appear in the table below.

2. Either select one or more columns for later formatting on the Create Masking Definition page, or formatting now if the data types of the columns you have selected are identical.

3. Optional: if you want to mask selected columns as a group, enable Mask selected columns as a group. The columns that you want to mask as a group must all be from the same table.

Enable this check box if you want to mask more than one column together, rather than separately. When you select two or more columns and then later define the format on the Define Group Mask page, the columns appear together, and any choices you make for format type or masking table apply collectively to all of the columns.

After you define the group and return to this page, the Column Group column in the table shows an identical number for each entry row in the table for all members of the group. For example, if you have defined your first group containing four columns, each of the four entries in this page will show a number 1 in the Column Group column. If you define another group, the entries in the page will show the number 2, and so forth. This helps you to distinguish which columns belong to which column groups.

4. Either click Add to add the column to the masking definition, return to the Create Masking Definition page and define the format of the column later, or click Define Format and Add to define the format for the column now.

The Define Format and Add feature can save you significant time. When you select multiple columns to add that have the same data type, you do not need to define the format for each column as you would when you click Add. For instance, if you search for Social Security numbers (SSN) and the search yields 100 SSN columns, you could select them all, then click Define Format and Add to import the SSN format for all of them.

5. Do one of the following:

- If you clicked Add in the previous step:

You will eventually need to define the format of the column in the Create Masking Definition page before you can continue. When you are ready to do so, click the icon in the page Format column for the column you want to format. Depending on whether you decided to mask selected columns as a group on the Add Columns page, either the Define Column mask or Define Group mask appears. Read further in this step for instructions for both cases.

- If you clicked Define Format and Add in the previous step and did not check Mask selected columns as a group:
The Define Column Mask page appears, where you can define the format for the column before adding the column to the Create Masking Definition page, as explained below:

- Provide a format entry for the required Default condition by either selecting a format entry from the list and clicking Add, or clicking Import Format, selecting a predefined format on the Import Format page, then clicking Import.
The Import Format page displays the formats that are marked with the same sensitive type as the masked column.

- Add another condition by clicking Add Condition to add a new condition row, then provide one or more format entries as described in the previous step.

- When you have finished formatting the column, click OK to return to the Create Masking Definition page.

- If you clicked Define Format and Add in the previous step and checked Mask selected columns as a group:
The Define Group Mask page appears, where you can add format entries for group columns that appear in the Create Masking Definition page, as explained below:

- Select one of the available format types. For complete information on the format types, see the online help for the Defining the Group Masking Format topic.

- Optionally add a column to the group.

- When you have finished formatting the group, click OK to return to the Create Masking Definition page.
The results appear in the Columns table. The sensitive columns you selected earlier now appear on this page. Primary key and foreign key columns appear below the sensitive columns.

Selecting Data Masking Advanced Options

The following options on the Masking Definitions page are all checked by default, so you need to uncheck the options that you do not want to enable:

- Data Masking Options

- Random Number Generation

- Pre- and Post-mask Scripts

Data Masking Options

The data masking options include:

- Disable redo log generation during masking
Masking disables redo logging and flashback logging to purge any original unmasked data from logs. However, in certain circumstances when you only want to test masking, roll back changes, and retry with more mask columns, it is easier to uncheck this box and use a flashback database to retrieve the old unmasked data after it has been masked. You can use Enterprise Manager to flashback a database.

Note:

Disabling this option compromises security. You must ensure this option is enabled in the final mask performed on the copy of the production database.

- Refresh statistics after masking
If you have already enabled statistics collection and would like to use special options when collecting statistics, such as histograms or different sampling percentages, it is beneficial to turn off this option to disable default statistics collection and run your own statistics collection jobs.

- Drop temporary tables created during masking
Masking creates temporary tables that map the original sensitive data values to mask values. In some cases, you may want to preserve this information to track how masking changed your data. Note that doing so compromises security. These tables must be dropped before the database is available for unprivileged users.

- Decrypt encrypted columns
This option decrypts columns that were previously masked using Encrypt format. To decrypt a previously encrypted column, the seed value must be the same as the value used to encrypt.

Decrypt only recovers the original value if the original format used for the encryption matches the original value. If the originally encrypted value did not conform to the specified regular expression, when decrypted, the encrypted value cannot reproduce the original value.

- Use parallel execution when possible
Oracle Database can make parallel various SQL operations that can significantly improve their performance. Data Masking uses this feature when you select this option. You can enable Oracle Database to automatically determine the degree of parallelism, or you can specify a value. For more information about using parallel execution and the degree of parallelism, see the Oracle Database Data Warehousing Guide.

- Recompile invalid dependent objects after masking
The masking process re-creates the table to be masked and as a consequence, all existing dependent objects (packages, procedures, functions, MViews, Views, Triggers) become invalid. You can specify that the masking process recompile these invalid objects after creating the table, by selecting the check box. Otherwise, invalid objects are not recompiled using utl_comp procedures at the end of masking.

If you choose this option, indicate whether to use serial or parallel execution. You can enable Oracle Database to automatically determine the degree, or you can specify a value. For more information about using parallel execution and the degree of parallelism, see the Oracle Database Data Warehousing Guide.

Random Number Generation

The random number generation options include:

- Favor Speed
The DBMS_RANDOM package is used for random number generation.

- Favor Security
The DBMS_CRYPTO package is used for random number generation. Additionally, if you use the Substitute format, a seed value is required when you schedule the masking job or database clone job.

Pre- and Post-mask Scripts

When masking a test system to evaluate performance, it is beneficial to preserve the object statistics after masking. You can accomplish this by adding a pre-masking script to export the statistics to a temporary table, then restoring them with a post-masking script after masking concludes.

Use the Pre Mask Script text box to specify any user-specified SQL script that must run before masking starts.

Use the Post Mask Script text box to specify any user-specified SQL script that must run after masking completes. Since masking modifies data, you can also perform tasks, such as rebalancing books or calling roll-up or aggregation modules, to ensure that related or aggregate information is consistent.

The following examples show pre- and post-masking scripts for preserving statistics.

This example shows a pre-masking script for preserving statistics.

variable sts_task  VARCHAR2(64);

/*Step :1 Create the staging table for statistics*/

exec dbms_stats.create_stat_table(ownname=>'SCOTT',stattab=>'STATS');

/* Step 2: Export the table statistics into the staging table. Cascade results
in all index and column statistics associated with the specified table being
exported as well. */

exec
dbms_stats.export_table_stats(ownname=>'SCOTT',tabname=>'EMP',
partname=>NULL,stattab=>'STATS',statid=>NULL,cascade=>TRUE,statown=>'SCOTT');
exec
dbms_stats.export_table_stats(ownname=>'SCOTT',tabname=>'DEPT',
partname=>NULL,stattab=>'STATS',statid=>NULL,cascade=>TRUE,statown=>'SCOTT');

/* Step 3: Create analysis task */
3. exec :sts_task := DBMS_SQLPA.create_analysis_task(sqlset_name=>
'scott_test_sts',task_name=>'SPA_TASK', sqlset_owner=>'SCOTT');

/*Step 4: Execute the analysis task before masking */
exec DBMS_SQLPA.execute_analysis_task(task_name => 'SPA_TASK',
execution_type=> 'explain plan', execution_name  => 'pre-mask_SPA_TASK');

This example shows a post-masking script for preserving statistics.

*Step 1: Import the statistics from the staging table to the dictionary tables*/

exec
dbms_stats.import_table_stats(ownname=>'SCOTT',tabname=>'EMP',
partname=>NULL,stattab=>'STATS',statid=>NULL,cascade=>TRUE,statown=>'SCOTT');
exec
dbms_stats.import_table_stats(ownname=>'SCOTT',tabname=>'DEPT',
partname=>NULL,stattab=>'STATS',statid=>NULL,cascade=>TRUE,statown=>'SCOTT');

/* Step 2: Drop the staging table */

exec dbms_stats.drop_stat_table(ownname=>'SCOTT',stattab=>'STATS');

/*Step 3: Execute the analysis task before masking */
exec DBMS_SQLPA.execute_analysis_task(task_name=>'SPA_TASK',
execution_type=>'explain plan', execution_name=>'post-mask_SPA_TASK');

/*Step 4: Execute the comparison task */
exec DBMS_SQLPA.execute_analysis_task(task_name =>'SPA_TASK',
execution_type=>'compare', execution_name=>'compare-mask_SPA_TASK');

See Also:

"Masking a Test System to Evaluate Performance" for a procedure that explains how to specify the location of these scripts when scheduling a data masking job

Scheduling a Script Generation Job

To schedule a script generation job:

1. Select the masking definition to generate a script for, then click Generate Script.

2. Change the default job name to something meaningful, if desired, and provide an optional job description.

3. Select a reference database from the drop-down list.

4. Select a script generation option:

- In-Place Masking–to replace sensitive data in-place with masked data on a specified database (usually copied from production). Use this option only in nonproduction environments. This differs from the Actions menu option Clone Database, which clones the database and then masks the data.

- At-Source Masking–to export masked data from the specified source database (usually production) using Oracle Data Pump. This option is safe to run in a production environment as it does not modify customer data. Note, however, that this option creates temporary tables that get dropped when the masking operation completes.

Note that you can choose both options; that is, a script to mask the database directly and a script to create a masked dump.

5. Specify a tablespace for temporary objects. Accept the default or select a tablespace where it might be easier to remove sensitive data.

6. Specify credentials to log in to the reference database.

7. Specify to start the job immediately or at a later specified date and time, then click Submit.

A message confirms that the job has been scheduled. Refresh the page to see the job results.

Scheduling a Data Masking Job

To set up the data masking job and schedule its execution:

1. Select the masking definition for which a script has been generated, then click Schedule Job.

2. Change the default job name if desired and enter an optional job description.

3. Select a database from the drop-down menu and indicate your preference:

- In-Place Masking–to replace sensitive data in-place with masked data on a specified database (usually copied from production). Use this option only in nonproduction environments. This differs from the Actions menu option Clone Database, which clones the database and then masks the data.

- At-Source Masking–to export masked data from the specified source database (usually production) using Oracle Data Pump. This option is safe to run in a production environment as it does not modify customer data. Note, however, that this option creates temporary tables that get dropped when the masking operation completes.

Your selections affect the check box text that appears below the radio buttons as well as other regions on the page.

4. Proceed according to your selections in Step 3:

- Data Mask Options–Provide the requisite information as follows:

- After script generation completes, the data masking script is stored in the Enterprise Manager repository. By default, the data masking job retrieves the script from the repository and copies it to the $ORACLE_HOME/dbs directory on the database host, using a generated file name. The Script File Location and Name fields enable you to override the default location and generated file name.

- Workloads–Select options to mask SQL tuning sets and capture files, as appropriate. Browse to the file location where you want to capture the files.

- Detect SQL Plan Changes Due to Masking–Run the SQL Performance Analyzer to assess the impact of masking. Provide a task name and browse to the corresponding SQL tuning set.

- Data Export Options–Provide the requisite information as follows:

- Specify a directory where to save the mask dump. The drop-down list consists of directory objects that you can access. Alternatively, you can select a custom directory path. Click the check box if you want to speed the process by using an external directory. Recommended default: DATA_FILE_DIR.

- Specify appropriate values if you want to override the defaults: enter a name for the export file; specify a maximum file size in megabytes; specify the maximum number of threads of active execution operating on behalf of the export job. This enables you to consider trade-offs between resource consumption and elapsed time.

- Select whether to enable dump file compression and encryption. Enter and confirm an encryption password, if appropriate. Log file generation is selected by default.

5. Specify credentials to log in to the database host.

6. Specify credentials to log in to the reference database.

7. Specify to start the job immediately or at a later specified date and time, then click Submit.

A message confirms that the job has been scheduled. Refresh the page to see the job results.

Estimating Space Requirements for Masking Operations

Here are some guidelines for estimating space requirements for masking operations. These estimates are based on a projected largest table size of 500GB. In making masking space estimates, assume a "worst-case scenario."

- For in-place masking:

- 2 * 500GB for the mapping table (the mapping table stores both the original and the masked columns. Worse case is every column is to be masked).

- 2 * 500GB to accommodate both the original and the masked tables (both exist in the database at some point during the masking process).

- 2 * 500GB for temporary tablespace (needed for hash joins, sorts, and so forth).

Total space required for the worst case: 3TB.

- For at-source masking:

- 2 * 500GB for the mapping table (as for in-place masking).

- 2 * 500GB for temporary tablespace (as for in-place masking).

- Sufficient file system space to accommodate the dump file.

Total space required for the worst case: 2TB plus the necessary file system space.

In either case, Oracle recommends that you set the temp and undo tablespaces to auto extend.

You can specify a tablespace for mapping tables during script generation. If you do not specify a tablespace, the tables are created in the tablespace of the executing user. Note that space estimations are provided during script generation, with resource warnings as appropriate. There are some situations, for example when using the shuffle format, that do not require a mapping table. In these cases, updates to the original table happen in-line.

Adding Dependent Columns

Dependent columns are defined by adding them to the Application Data Model. The following prerequisites apply for the column to be defined as dependent:

- A valid dependent column should not already be included for masking.

- The column should not be a foreign key column or referenced by a foreign key column.

- The column data should conform to the data in the parent column.

If the column does not meet these criteria, an "Invalid Dependent Columns" message appears when you attempt to add the dependent column.

Masking Dependent Columns for Packaged Applications

The following procedure explains how to mask data across columns for packaged applications in which the relationships are not defined in the data dictionary.

To mask dependent columns for packaged applications:

1. Go to Data Discovery and Modeling and create a new Application Data Model (ADM) using metadata collection for your packaged application suite.
When metadata collection is complete, edit the newly created ADM.

2. Manually add a referential relationship:

a. From the Referential Relationships tab, open the Actions menu, then select Add Referential Relationship.
The Add Referential Relationship pop-up window appears.

b. Select the requisite Parent Key and Dependent Key information.

c. In the Columns Name list, select a dependent key column to associate with a parent key column.

d. Click OK to add the referential relationship to the ADM.
The new dependent column now appears in the referential relationships list.

3. Perform sensitive column discovery.
When sensitive column discovery is complete, review the columns found by the discovery job and mark them sensitive or not sensitive as needed.

When marked as sensitive, any discovery sensitive column also marks its parent and the other child columns of the parent as sensitive. Consequently, it is advisable to first create the ADM with all relationships. ADM by default, or after running drivers, may not contain denormalized relationships. You need to manually add these.

For more information about sensitive column discovery, see step 6.

4. Go to Data Masking and create a new masking definition.

5. Select the newly created ADM and click Add, then Search to view this ADM's sensitive columns.

6. Select columns based on your search results, then import formats for the selected columns.
Enterprise Manager displays formats that conform to the privacy attributes.

7. Select the format and generate the script.

8. Execute the masking script.
Enterprise Manager executes the generated script on the target database and masks all of your specified columns.

Cloning the Production Database

When you clone and mask the database, a copy of the masking script is saved in the Enterprise Manager repository and then retrieved and executed after the clone process completes. Therefore, it is important to regenerate the script after any schema changes or modifications to the production database.

To clone and optionally mask the masking definition's target database:

1. From the Data Masking Definitions page, select the masking definition you want to clone, select Clone Database from the Actions list, then click Go.
The Clone Database: Source Type page appears.

The Clone Database wizard appears, where you can create a test system to run the mask.

2. Specify the type of source database backup to be used for the cloning operation, then click Continue.

3. Proceed through the wizard steps as you ordinarily would to clone a database. For assistance, refer to the online help for each step.

4. In the Database Configuration step of the wizard, add a masking definition, then select the Run SQL Performance Analyzer option as well as other options as desired or necessary.

5. Schedule and then run the clone job.

Importing a Data Masking Template

You can import and re-use a previously exported data masking definition saved as an XML file to the current Enterprise Manager repository. You also can import an Oracle-supplied data masking definition from the Software Library.

Importing a Previously Exported Masking Definition

Note the following advisory information:

- The XML file format must be compliant with the masking definition XML format.

- Verify that the name of the masking definition to be imported does not already exist in the repository, and the source database name identifies a valid Enterprise Manager target.

- Verify that the value in the XML file to be imported refers to a valid database target.

1. From the Data Masking Definitions page, click Import.
The Import Masking Definition page appears.

2. Specify a name for the masking definition and select the ADM to associate with the template. The Reference Database is automatically provided.

3. Browse for the XML file, or specify the name of the XML file, then click Continue.
The Data Masking Definitions Page reappears and displays the imported definition in the table list for subsequent viewing and masking.

Importing a Data Masking Template from the Software Library

The Self Update feature ensures that the latest Oracle-supplied data masking templates are available in the Software Library. You can also check for updates. Go to the Self Update page and check for Test Data Management updates. If present, download and apply them so that they are available in the Software Library.

1. On the Data Masking Definitions page, click Import from Software Library.
The Import Masking Definition page appears.

2. Select a masking template in the Software Library list.

3. Specify a name for the masking definition and select the ADM to associate with the template. The Reference Database is automatically provided.

4. Click Continue.
The Data Masking Definitions Page reappears and displays the imported definition in the table list for subsequent viewing and masking.

You can also export a data masking definition from the Software Library.

1. On the Data Masking Definitions page, click Export from Software Library.

2. Select a masking template in the Software Library list.

3. Click Export.

Save the template file for import into a different repository.

Masking a Test System to Evaluate Performance

After you have created a data masking definition, you may want to use it to analyze the performance impact from masking on a test system. The procedures in the following sections explain the process for this task for masking only, or cloning and masking.

Using Only Masking for Evaluation

To use only masking to evaluate performance:

1. From the Data Masking Definitions page, select the masking definition to be analyzed, then click Schedule Job.
The Schedule Data Masking Job page appears.

2. At the top of the page, provide the requisite information.

The script file location pertains to the masking script, which also contains the pre- and post-masking scripts you created in "Pre- and Post-mask Scripts".

3. In the Encryption Seed section, provide a text string that you want to use for encryption.
This section only appears for masking definitions that use the Substitute or Encrypt formats. The seed is an encryption key used by the encryption/hash-based substitution APIs, and makes masking more deterministic instead of being random.

4. In the Workloads section:

a. Select the Mask SQL Tuning Sets option, if desired.
If you use a SQL Tuning Set that has sensitive data to evaluate performance, it is beneficial to mask it for security, consistency of data with the database, and to generate correct evaluation results.

b. Select the Capture Files option, if desired, then select a capture directory.
When you select this option, the contents of the directory is masked. The capture file masking is executed consistently with the database.

5. In the Detect SQL Plan Changes Due to Masking section, leave the Run SQL Performance Analyzer option unchecked.
You do not need to enable this option because the pre- and post-masking scripts you created, referenced in step 2, already execute the analyzer.

6. Provide credentials and scheduling information, then click Submit.
The Data Masking Definitions page reappears, and a message appears stating that the Data Masking job has been submitted successfully.

During masking of any database, the AWR bind variable data is purged to protect sensitive bind variables from leaking to a test system.

7. When the job completes successfully, click the link in the SQL Performance Analyzer Task column to view the executed analysis tasks and Trial Comparison Report, which shows any changes in plans, timing, and so forth.

Using Cloning and Masking for Evaluation

Using both cloning and masking to evaluate performance is very similar to the procedure described in the previous section, except that you specify the options from the Clone Database wizard, rather than from the Schedule Data Masking Job page.

To use both cloning and masking to evaluate performance:

1. Follow the steps described in "Cloning the Production Database".

2. At step 4, the format of the Database Configuration step appears different from the Schedule Data Masking Job page discussed in "Using Only Masking for Evaluation", but select options as you would for the Schedule Data Masking Job page.

3. Continue with the wizard steps to complete and submit the cloning and masking job.

Upgrade Considerations

Upgrading data masking definitions from 10 or 11 Grid Control to 12c Cloud Control assumes that you have completed the following tasks:

- Upgraded Enterprise Manager to 12c

- Downloaded the latest database plug-in using Self Update and deployed the plug-in to OMS and Management Agent

Completing these tasks automatically upgrades the masking definitions and creates for each a shell Application Data Model (ADM) that becomes populated with the sensitive columns and their dependent column information from the legacy mask definition. The ADM, and hence data masking, then remains in an unverified state, because it is missing the dictionary relationships.

Proceed as follows to complete the masking definition upgrade:

1. From the Enterprise menu, select Quality Management, then select Data Discovery and Modeling.

2. For each shell ADM (verification status is Needs Upgrade), do the following:

a. Select the ADM in the table.

b. From the Actions menu, select Upgrade and Verify.

c. Schedule and submit the job.
When the job completes, verification status should be Valid.

3. From the Enterprise menu, select Quality Management, then select Data Masking Definitions.

4. For each upgraded masking definition, do the following:

a. Open the masking definition for editing.

b. In Advanced Options, select the "Recompile invalid dependent objects after masking" option, with Parallel and Default settings.

c. Click OK to save your changes.

5. Next, schedule a script generation job for each upgraded masking definition.

You can now resume masking with the upgraded data masking definitions.

See Also:

"Adding Dependent Columns" for information on dependent columns

Consider these other points regarding upgrades:

- You can combine multiple upgraded ADMs by exporting an ADM and performing an Import Content into another ADM.

- An upgraded ADM uses the same semantics as for upgrading a legacy mask definition (discussed above), in that you would need to perform a validation.

- An 11.1 Grid Control E-Business Suite (EBS) masking definition based on an EBS masking template shipped from Oracle is treated as a custom application after the upgrade. You can always use the approach discussed in the first bulleted item above to move into a newly created EBS ADM with all of the metadata in place. However, this is not required.

Using the Shuffle Format

A shuffle format is available that does not preserve data distribution when the column values are not unique and also when it is conditionally masked. For example, consider the Original Table (Table 19-1) that shows two columns: EmpName and Salary. The Salary column has three distinct values: 10, 90, and 20.

Table 19-1 Original Table (Non-preservation)

EmpName

Salary

A

10

B

90

C

10

D

10

E

90

F

20

If you mask the Salary column with this format, each of the original values is replaced with one of the values from this set. Assume that the shuffle format replaces 10 with 20, 90 with 10, and 20 with 90 (Table 19-2).

Table 19-2 Mapping Table (Non-preservation)

EmpName

Salary

10

20

90

10

20

90

The result is a shuffled Salary column as shown in the Masked Table (Table 19-3), but the data distribution is changed. While the value 10 occurs three times in the Salary column of the Original Table, it occurs only twice in the Masked Table.

Table 19-3 Masked Table (Non-preservation)

EmpName

Salary

A

20

B

10

C

20

D

20

E

10

F

90

If the salary values had been unique, the format would have maintained data distribution.

Using Group Shuffle

Group shuffle enables you to perform a shuffle within discrete units, or groups, where there is a relationship among the members of the group. Consider the case of shuffling the salaries of employees. Table 19-4illustrates the group shuffle mechanism, where employees are categorized as managers (M) or workers (W), and salaries are shuffled within job category.

Table 19-4 Group Shuffle Using Job Category

Employee

Job Category

Salary

Shuffled Salary

Alice

M

90

88

Bill

M

88

90

Carol

W

72

70

Denise

W

57

45

Eddie

W

70

57

Frank

W

45

72

Using Conditional Masking

To demonstrate how conditional masking can handle duplicate values, add to Table 19-4 another job category, assistant (A), where the employee in this category, George, earns the same as Frank. Assume the following conditions:

- If job category is M, replace salary with a random number between 1 and 10.

- If job category is W, set salary to a fixed number (01).

- Default is to preserve the existing value.

Applying these conditions results in the masked values shown in Table 19-5:

Table 19-5 Using Job Category for Group Shuffle

Employee

Job Category

Salary

Conditional Result

Alice

M

90

5

Bill

M

88

7

Carol

W

72

01

Denise

W

57

01

Eddie

W

70

01

Frank

W

45

01

George

A

45

45

Conditional masking works when there are duplicate values provided there are no dependent columns or foreign keys. If either of these is present, a "bleeding condition" results in the first of two duplicate values becoming the value of the second. So, in the example, George's salary is not preserved, but becomes 01.

Using Data Masking with LONG Columns

When data masking script generation completes, an impact report appears. If the masking definition has tables with columns of data type LONG, the following warning message is displayed in the impact report:

The table <table_name> has a LONG column. Data Masking uses "in-place" UPDATE
to mask tables with LONG columns. This will generate undo information and the
original data will be available in the undo tablespaces during the undo
retention period. You should purge undo information after masking the data.
Any orphan rows in this table will not be masked.

Index

A  C  D  E  H  I  M  O  P  R  S  U  V  W

A

- Application Data Model (ADM)

- application tables, viewing and editing [1]

- associating a database to [1] , [2]

- creating

- prerequisites for [1]

- definition of [1]

- discovering sensitive columns [1] , [2]

- editing application tables [1]

- manually adding referential relationships [1] , [2]

- relationship to other TDM components [1]

- sensitive columns

- automatically discovering [1]

- changing the type for [1]

- creating a type for [1]

- manually adding [1]

- source database status [1]

- upgrading [1]

- verifying source database [1]

- viewing application tables [1]

- viewing referential relationships [1]

C

- capture subset

- about [1]

- generating [1]

- changing the type for sensitive columns [1]

- cloning production database in data masking [1]

- Consolidated Database Replay

- about [1]

- connection remapping [1] , [2]

- consolidated replay directory

- setting [1]

- initializing [1]

- preparing [1]

- replay options [1]

- reporting [1]

- running [1]

- sample scenario [1]

- starting [1]

- steps [1]

- test system

- capture directory [1]

- setting up [1]

- user remapping [1] , [2]

- using with APIs [1]

- workload captures

- supported [1]

- creating

- Application Data Model (ADM) [1]

- data masking definition [1]

- data subset definition [1]

- masking definition [1]

- masking formats [1]

- sensitive column type [1]

D

- data, hiding with data masking [1]

- Database Lifecycle Management Pack [1]

- Database Replay

- about [1]

- methodology [1]

- replay clients

- about [1] , [2]

- calibrating [1]

- starting [1] , [2]

- replay filter set

- about [1]

- reporting

- replay compare period reports [1] , [2]

- SQL Performance Analyzer reports [1]

- workload capture report [1]

- workload replay report [1]

- usage [1] , [2]

- workflow [1]

- workload capture

- about [1]

- capture directory [1]

- capture files [1]

- capturing [1] , [2] , [3] , [4]

- exporting data [1]

- importing data [1]

- managing [1]

- monitoring [1] , [2]

- options [1]

- prerequisites [1]

- reporting [1]

- restarting the database [1]

- restrictions [1]

- stopping [1] , [2]

- workload filters

- about [1] , [2]

- defining [1]

- exclusion filters [1] , [2]

- inclusion filters [1] , [2]

- workload preprocessing

- about [1] , [2]

- preprocessing [1]

- workload replay

- about [1] , [2]

- cancelling [1]

- exporting data [1]

- filters [1]

- importing data [1]

- monitoring [1] , [2]

- options [1] , [2]

- pausing [1]

- replaying [1] , [2]

- reporting [1]

- resuming [1]

- starting [1]

- steps [1]

- database upgrades

- testing [1]

- database version

- production system [1] , [2]

- system running SQL Performance Analyzer [1] , [2]

- test system [1] , [2]

- data masking

- adding columns to a masking definition [1]

- advanced options [1]

- auto mask [1]

- Canadian social insurance numbers [1]

- cloning and masking [1]

- cloning the production database [1] , [2]

- Create Masking Definition page [1]

- creating formats [1]

- creating masking definition [1] , [2]

- Data Masking Definitions page [1]

- Define Column Mask page [1]

- defining new formats [1]

- dependent columns, adding [1]

- description [1]

- deterministic masking [1]

- DM_FMTLIB package, installing [1]

- encryption seed [1]

- evaluating performance [1]

- format entry options [1]

- importing data masking templates [1]

- ISBN numbers [1]

- major task steps [1]

- mask format libraries, description of [1]

- masking definitions, description of [1]

- masking dependent columns [1]

- masking format templates, using [1]

- masking selected columns as a group [1]

- minimum privileges [1]

- North American phone numbers [1]

- other Oracle security products [1]

- patterns of format definitions [1]

- post-processing functions [1]

- pre- and post-masking scripts [1]

- predefined masking formats [1]

- primary key [1]

- random number generation options [1]

- security administrator [1]

- shuffle format examples [1]

- social security numbers [1]

- staging region [1]

- substitute format [1]

- supported data types [1]

- UK national insurance numbers [1]

- UPC numbers [1]

- upgrading [1]

- using with LONG columns [1]

- workflow [1]

- data subsetting

- Ancestor and Descendant Tables [1]

- Ancestor Tables Only [1]

- creating a definition [1]

- exporting subset templates [1]

- generating a subset [1]

- importing subset templates [1]

- providing rules [1]

- required privileges [1] , [2]

- saving a subset script [1]

- space estimates [1]

- specifying Where clause [1]

- DBMS_SPM package

- LOAD_PLANS_FROM_SQLSET function [1]

- DBMS_SQLPA package

- CREATE_ANALYSIS_TASK function [1]

- EXECUTE_ANALYSIS_TASK procedure [1] , [2] , [3] , [4] , [5]

- REPORT_ANALYSIS_TASK function [1]

- SET_ANALYSIS_TASK_PARAMETER procedure [1] , [2] , [3]

- DBMS_SQLTUNE package

- CREATE_TUNING_TASK function [1]

- SELECT_SQL_TRACE function [1]

- DBMS_WORKLOAD_CAPTURE package

- ADD_FILTER procedure [1]

- DELETE_FILTER procedure [1]

- EXPORT_AWR procedure [1]

- FINISH_CAPTURE procedure [1]

- GET_CAPTURE_INFO procedure [1]

- IMPORT_AWR function [1]

- START_CAPTURE procedure [1]

- DBMS_WORKLOAD_REPLAY package

- ADD_CAPTURE function [1]

- ADD_FILTER procedure [1]

- ADD_SCHEDULE_ORDERING function [1]

- BEGIN_REPLAY_SCHEDULE procedure [1]

- CANCEL_REPLAY procedure [1]

- COMPARE_PERIOD_REPORT procedure [1]

- COMPARE_SQLSET_REPORT procedure [1]

- CREATE_FILTER_SET procedure [1]

- DELETE_FILTER procedure [1]

- DELETE_REPLAY_INFO function [1]

- END_REPLAY_SCHEDULE procedure [1]

- EXPORT_AWR procedure [1]

- GENERATE_CAPTURE_SUBSET procedure [1]

- GET_DIVERGING_STATEMENT function [1]

- GET_REPLAY_DIRECTORY function [1]

- GET_REPLAY_INFO function [1] , [2]

- IMPORT_AWR function [1]

- INITIALIZE_REPLAY procedure [1]

- INITIALIZED_CONSOLIDATED_REPLAY procedure [1]

- LOAD_DIVERGENCE procedure [1]

- PAUSE_REPLAY procedure [1]

- PREPARE_CONSOLIDATED_REPLAY procedure [1]

- PREPARE_REPLAY procedure [1]

- PROCESS_CAPTURE procedure [1]

- REMAP_CONNECTION procedure [1] , [2]

- REMOVE_CAPTURE procedure [1]

- RESUME_REPLAY procedure [1]

- SET_CONSOLIDATED_DIRECTORY procedure [1]

- SET_REPLAY_TIMEOUT procedure [1]

- SET_USER_MAPPING procedure [1] , [2]

- START_CONSOLIDATED_REPLAY procedure [1]

- START_REPLAY procedure [1]

- USE_FILTER_SET procedure [1]

- deterministic masking [1]

- discovering sensitive columns [1] , [3]

E

- editing application tables [1]

- exporting

- subset templates, data subsetting [1]

H

- hiding data using data masking [1]

I

- importing

- data masking templates [1]

- subset templates, data subsetting [1]

M

- manually adding sensitive columns [1]

- mapping table

- about [1]

- creating [1] , [2]

- moving [1] , [2]

- mask format libraries [1]

- masking definitions

- credit card numbers [1]

- masking formats

- entry options [1]

- predefined [1]

O

- Oracle Data Masking and Subsetting Pack [1] , [2] , [3]

P

- post-processing functions, data masking [1]

- prerequisites for creating an ADM [1]

- primary key, data masking and [1]

- privileges

- data subsetting [1]

- minimum for data masking [1]

R

- Real Application Testing

- about [1]

- components [1]

- referential relationships

- manually adding [1] , [2]

- viewing [1]

- regulatory compliance using masked data [1]

- replay schedule

- about [1]

- defining [1] , [2]

- saving [1]

- schedule orders

- adding [1]

- removing [1]

- workload captures

- adding [1]

- removing [1]

- Right to Financial Privacy Act of 1978 [1]

S

- Sarbanes-Oxley regulatory requirements [1]

- schedule order

- about [1]

- viewing [1]

- Secure Test Data Management [1]

- security

- compliance with masked data [1]

- data masking [1]

- list of Oracle products [1]

- mask format libraries [1]

- masking definitions [1]

- security administrator, data masking and [1]

- sensitive columns

- changing the type for [1]

- creating the type for [1]

- discovering [1] , [2]

- discovering automatically [1]

- manually adding [1]

- performing discovery of [1]

- SPA Quick Check

- configuring [1]

- specifying default values [1]

- using [1]

- validating initialization parameter changes [1]

- validating key SQL profiles [1]

- validating pending optimizer statistics [1]

- validating statistics findings [1]

- SQL Performance Analyzer

- about [1]

- comparing execution plans [1]

- comparing performance [1] , [2] , [3]

- configuring a task [1]

- creating a task [1] , [2] , [3]

- executing the SQL workload [1] , [2]

- executing the SQL workload after a change [1] , [2]

- initial environment

- establishing [1]

- input source [1]

- making a change [1]

- methodology [1]

- monitoring [1]

- performance data

- collecting post-change version [1]

- collecting pre-change version [1]

- comparing [1]

- remote test execution [1] , [2]

- reporting [1]

- setting up the test system [1]

- SQL Performance Analyzer report

- active reports [1]

- general information [1] , [2]

- global statistics [1]

- global statistics details [1]

- result details [1]

- result summary [1]

- reviewing [1] , [2]

- SQL tuning set

- selecting [1] , [2]

- SQL workload

- capturing [1]

- executing [1] , [2]

- transporting [1]

- system change

- making [1]

- task

- creating [1] , [2]

- usage [1]

- using [1]

- workflow

- Exadata simulation [1]

- guided [1]

- optimizer statistics [1]

- parameter change [1]

- SQL Performance Analyzer Quick Check

- See: SPA Quick Check

- SQL plan baselines

- creating [1]

- SQL statements

- regressed [1] , [2] , [3] , [4] , [5] , [6] , [7] , [8]

- SQL Trace

- about [1]

- enabling [1] , [2]

- trace level [1]

- SQL trace files

- about [1]

- moving [1] , [2]

- SQL trials

- about [1] , [2]

- building

- post-upgrade version [1] , [2] , [3]

- pre-upgrade version [1] , [2] , [3] , [4]

- comparing [1]

- SQL tuning set

- about [1]

- building [1]

- comparing [1]

- constructing [1]

- converting [1]

- staging region, data masking and [1]

- statuses for Source Database Status column, ADM [1]

- substitute format, data masking and [1]

- supported data types, data masking [1]

U

- upgrade environment [1] , [2]

- upgrading

- ADM [1]

- data masking [1]

V

- verifying source database, ADM [1]

- viewing

- application tables [1]

- referential relationships [1]

W

- Where clause, specifying for data subsetting [1]

- Workload Analyzer

- about [1]

- running [1]

- Workload Intelligence

- about [1] , [2]

- BuildModel program

- options [1]

- syntax [1]

- creating a database user [1]

- creating a job [1]

- creating a workload model [1]

- FindPatterns program

- about [1]

- options [1]

- syntax [1]

- GenerateReport program

- about [1]

- options [1]

- syntax [1]

- generating report [1]

- identifying patterns [1]

- LoadInfo program

- about [1]

- options [1]

- syntax [1]

- pattern [1]

- sample scenario [1]

- template [1]

- using [1]

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