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Contents

Title and Copyright Information

Preface

• Audience
• Documentation Accessibility
• Related Documents
• Conventions

1 Introduction

• The Information Integration Challenge
• How Oracle Addresses Synchronous Information Integration
• Benefits of Oracle's Solution for Synchronous Information Integration
  • Remote Data Can Be Accessed Transparently
  • No Unnecessary Data Duplication
  • SQL Statements Can Query Several Different Databases
  • Oracle's Application Development and End User Tools Can Be Used
  • Users Can Communicate With a Remote Database in its Own Language

2 The Role of the Heterogeneous Services Component

• Heterogeneous Connectivity Process Architecture
• Heterogeneous Services Agents
• Types of Heterogeneous Services Agents
  • Oracle Database Gateways
  • Oracle Database Gateway for ODBC Agent
• Heterogeneous Services Components
  • Transaction Service
  • SQL Service
• Heterogeneous Services Configuration Information
  • Data Dictionary Translation Views
  • Heterogeneous Services Initialization Parameters
  • Capabilities
• Heterogeneous Services Data Dictionary
  • Classes and Instances
  • Data Dictionary Views
• Gateway Process Flow

3 Features of Oracle Database Gateways

• SQL and PL/SQL Support
• Heterogeneous Replication
  • Creating Materialized Views for Heterogeneous Replication Example
  • Setting Up a Refresh Group for Heterogeneous Replication Example
  • Forcing Refresh of All Three Materialized Views Example
• Passthrough SQL
  • DBMS_HS_PASSTHROUGH Package
  • Implications of Using Passthrough SQL
  • Execute Passthrough SQL Statements
• Result Set Support
  • Result Set Support for Non-Oracle Systems
  • Heterogeneous Services Support for Result Sets
• Data Dictionary Translations
• Date-Time Data Types
• Two-Phase Commit Protocol
• Piecewise LONG Data Type
• SQL*Plus DESCRIBE Command
• Constraints on SQL in a Distributed Environment
  • Remote and Heterogeneous References
  • Rules and Restrictions When Using SQL for Remote Mapping in a Distributed Environment
• Oracle's Optimizer and Heterogeneous Services
  • Using Index and Table Statistics Example
  • Remote Join Optimization Example
  • Optimizer Restrictions for Non-Oracle Access
  • Explain Plan Consideration

4 Using Heterogeneous Services Agents

• Initialization Parameters
  • Encrypting Initialization Parameters
  • Gateway Initialization Parameters
• Optimize Data Transfers Using Bulk Fetch
  • Use OCI, an Oracle Precompiler, or Another Tool for Array Fetches
  • Control the Array Fetch Between Oracle Database and the Agent
  • Control the Array Fetch Between the Agent and the Non-Oracle System
  • Control the Reblocking of Array Fetches
• Optimizing Data Loads Using Parallel Load
• Registering Agents
  • Enabling Agent Self-Registration
  • Disabling Agent Self-Registration
• Oracle Database Server SQL Construct Processing
  • Data Type Checking Support for a Remote-Mapped Statement
• Executing User-Defined Functions on a Non-Oracle Database
• Synonyms
  • Example: A Distributed Query
• Copy Data from the Oracle Database Server to the Non-Oracle Database System
• Copy Data from the Non-Oracle Database System to the Oracle Database Server
• Heterogeneous Services Data Dictionary Views
  • Types of Views
  • Sources of Data Dictionary Information
  • General Views
  • Transaction Service Views
  • SQL Service Views
• Heterogeneous Services Dynamic Performance Views
  • Determine Which Agents Are Running on a Host: V$HS_AGENT View
  • Determine the Open Heterogeneous Services Sessions: V$HS_SESSION View
  • Determine the Heterogeneous Services Parameters: V$HS_PARAMETER View

5 Performance Recommendations

• Optimize Heterogeneous Distributed SQL Statements
• Optimize Performance of Distributed Queries

Index