Database Backup and Recovery Reference
ContentsOpens a new window
Opens a new window
Page 23 of 152

DELETE

Purpose

Use the DELETE command to perform the following actions:

  • Delete physical backups and copies.

  • Update the repository records in the target control file to show that the files are deleted. For example, the record for a backup piece in V$BACKUP_PIECE.STATUS shows the value D.

  • Remove the repository records for deleted files from the recovery catalog (if you use a catalog). For example, RC_BACKUP_PIECE no longer contains a row for a deleted backup piece.

See Also:

BACKUPOpens a new window to learn about the BACKUP ... DELETE INPUT command

Prerequisites

RMAN must be connected to a target database, which must be mounted or open.

RMAN uses all configured channels to perform the deletion. If you use DELETE for files on devices that are not configured for automatic channels, then you must use ALLOCATE CHANNEL FOR MAINTENANCEOpens a new window. For example, if you made a backup with an SBT channel, but only a disk channel is configured, then you must manually allocate an SBT channel for DELETE. An automatic or manually allocated maintenance channel is required when you use DELETE on a disk-only file.

Usage Notes

The best practice is to run CROSSCHECKOpens a new window to update the status of backups and copies in the repository and then run DELETE to remove the desired files. When running RMAN interactively, DELETE displays a list of files and prompts for confirmation before deleting any file in the list. If you confirm, then RMAN shows each item as it is deleted. When reading commands from a command file, RMAN does not prompt for confirmation.

You can view the status of backups and copies recorded in the RMAN repository through LISTOpens a new window, V$ views, or recovery catalog views (if you use a catalog). The repository record for a backup can fail to reflect its physical status. For example, a user deletes a disk backup with the Linux rm command. The backup record cannot be updated by rm, so the RMAN repository shows the file as available although it no longer exists.

Behavior of DELETE Command for Files of Different Status Values

Table 2-5Opens a new window describes the behavior of DELETE when the FORCE option is not specified.

Table 2-5 Behavior of DELETE Command Without FORCE Option

Repository Status Physical Status Behavior of DELETE Command

AVAILABLE

Not found on media

Does not delete the object and reports the list of mismatched objects at the end of the job. RMAN does not update the repository status.

EXPIRED

Found on media

Does not delete the object and reports the list of mismatched objects at the end of the job. RMAN does not update the repository status.

UNAVAILABLE

Any

Removes repository record and deletes object if it exists. All I/O errors are ignored.

Backup Deletion in a Data Guard Environment

"RMAN Backups in a Data Guard Environment"Opens a new window explains the difference between the association and accessibility of a backup. In a Data Guard environment, the database that creates a backup or copy is associated with the file. You can use maintenance commands such as CHANGE, DELETEOpens a new window, and CROSSCHECKOpens a new window for backups when connected to any database in the Data Guard environment if the backups are accessible. In general, RMAN considers tape backups created on any database as accessible to all databases in the environment, whereas disk backups are accessible only to the database that created them.

If a deletion is successful, then RMAN removes the metadata for the file, even if the file is associated with another database. If a deletion was not successful, and if the file is associated with another database in the Data Guard environment, then RMAN prompts you to perform the same DELETE command while connected as TARGET to the database associated with the file. You must use DELETE ... FORCE to delete the file metadata.

Syntax

delete::=

Description of delete.gif follows
Description of the illustration delete.gifOpens a new window

(maintSpec::=Opens a new window, obsOperandList::=Opens a new window, deviceSpecifier::=Opens a new window)

maintSpecOpens a new window::=

Description of maintspec.gif follows
Description of the illustration maintspec.gifOpens a new window

(listObjList::=Opens a new window, archivelogRecordSpecifier::=Opens a new window, maintQualifier::=Opens a new window, deviceSpecifier::=Opens a new window, recordSpec::=Opens a new window)

forDbUniqueNameOption::=Opens a new window

Description of fordbuniquenameoption.gif follows
Description of the illustration fordbuniquenameoption.gifOpens a new window

Semantics

Syntax Element Description
FORCE Deletes specified files—whether or not they exist on the media—and removes repository records (see Example 2-78Opens a new window).

RMAN ignores any I/O errors for the deleted objects. RMAN also ignores any CONFIGUREOpens a new window ARCHIVELOG DELETION POLICYOpens a new window settings. RMAN displays the number of deleted objects at the end of the job.
NOPROMPT Deletes specified files without first listing the files or prompting for confirmation. The DELETE NOPROMPT command displays each item as it is deleted.
EXPIRED Removes only files whose status in the repository is EXPIRED (see Example 2-75Opens a new window). RMAN marks backups and copies as expired when you run a CROSSCHECK command and the files are absent or inaccessible. To determine which files are expired, run a LIST EXPIRED command.

If for some reason a backup marked EXPIRED exists when you run the DELETE EXPIRED command, then RMAN does not delete the physical file.
maintSpecOpens a new window Deletes backups and copies.

You can set rules for the deletion with the maintQualifierOpens a new window clause. For example, you can delete archived redo log files that are backed up to tape (see Example 2-77Opens a new window).

Note: DELETE ARCHIVELOG ALL considers only the archived log deletion policy and does not consider the configured retention policy.

Note: In CDBs, you must connect to the root as a user with the SYSDBA or SYSBACKUP privilege to delete archived redo logs. You cannot delete archived redo logs when connected to a PDB.

See Also: maintSpecOpens a new window and maintQualifierOpens a new window
   forDbUniqueNameOptionOpens a new window Deletes the backups and copies in maintSpecOpens a new window that are exclusively associated with the specified DB_UNIQUE_NAME in a Data Guard environment.

Note: The FOR DB_UNIQUE_NAME option is not allowed with the DELETE OBSOLETE command.

If RMAN successfully deletes tape backups associated with the specified DB_UNIQUE_NAME, then RMAN removes the metadata for these files from the recovery catalog. If RMAN could not delete these files because they are associated with a different database in the Data Guard environment, then RMAN prompts you to perform the same DELETE operation for these files at the database that is associated with them.

Note: You cannot use FORCE to override the default behavior and specify that RMAN deletes files that are associated with a different database. In this way, RMAN protects you from accidental deletions caused by incorrect RMAN configurations for SBT. To remove the metadata for files that RMAN prevents you from deleting, use the CHANGEOpens a new window RESET DB_UNIQUE_NAME command.

See Also: forDbUniqueNameOptionOpens a new window for descriptions of the options in this clause
OBSOLETE Deletes data file backups and copies recorded in the RMAN repository that are obsolete, that is, no longer needed (see Example 2-76Opens a new window). RMAN also deletes obsolete archived redo log files and log backups.

RMAN determines which backups and copies of data files are no longer needed, which in turn determines when logs (and backups of logs) are no longer needed. RMAN considers the creation of a data file as a backup when deciding which logs to keep.

RMAN first uses the options specified with obsOperandListOpens a new window to determine which files are obsolete. If you do not specify options in obsOperandListOpens a new window, then RMAN uses the options specified in CONFIGURE RETENTION POLICYOpens a new window.

Note: DELETE OBSOLETE considers only the backup retention policy and does not use the configured archived log deletion policy to determine which logs are obsolete. In contrast, DELETE ARCHIVELOG ALL considers only the configured archived log deletion policy.

Note: If you make a backup with the KEEP UNTIL TIME clause, then this backup becomes obsolete after the specified KEEP time passes and is removed by DELETE OBSOLETE. RMAN does not consider the backup retention policy for archival backups whose KEEP time has expired.

Note: The DELETE...OBSOLETE command cannot be used when backups are stored to Zero Data Loss Recovery Appliance, commonly known as Recovery Appliance.
   obsOperandListOpens a new window Specifies the criteria for determining which backups and copies are obsolete.

See Also: obsOperandListOpens a new window

   DEVICE TYPE
   deviceSpecifierOpens a new window		 Restricts the deletion to obsolete backups and copies created on the specified device type only.

See Also: deviceSpecifierOpens a new window

Examples

Example 2-75 Deleting Expired Backups

This example uses a configured sbt channel to check the media manager for expired backups of the tablespace users that are more than one month old and removes their recovery catalog records.

CROSSCHECK BACKUPSET OF TABLESPACE users 
  DEVICE TYPE sbt COMPLETED BEFORE 'SYSDATE-31';
DELETE NOPROMPT EXPIRED BACKUPSET OF TABLESPACE users 
  DEVICE TYPE sbt COMPLETED BEFORE 'SYSDATE-31';

Example 2-76 Deleting Obsolete Backups

This example deletes backups and copies that are not needed to recover the database to an arbitrary SCN within the last week. RMAN also deletes archived redo log files that are no longer needed.

DELETE NOPROMPT OBSOLETE RECOVERY WINDOW OF 7 DAYS;

Example 2-77 Deleting Archived Redo Log Files That Are Backed Up

Assume that you have configured RMAN settings as follows:

CONFIGURE DEFAULT DEVICE TYPE TO sbt;
CONFIGURE ARCHIVELOG DELETION POLICY TO
  BACKED UP 2 TIMES
  TO DEVICE TYPE sbt;

The following DELETE command deletes all archived redo log files on disk if they are not needed to meet the configured deletion policy, which specifies that logs must be backed up twice to tape (sample output included):

RMAN> DELETE ARCHIVELOG ALL;
 
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=84 device type=DISK

List of Archived Log Copies for database with db_unique_name PROD
=====================================================================
 
Key     Thrd Seq     S Low Time
------- ---- ------- - ---------
107     1    4       A 12-FEB-13
        Name: /orcva/PROD/archivelog/2013_02_12/o1_mf_1_4_2x28bpcm_.arc 
108     1    5       A 12-FEB-13
        Name: /orcva/PROD/archivelog/2013_02_12/o1_mf_1_5_2x28g7s9_.arc
109     1    6       A 12-FEB-13
        Name: /orcva/PROD/archivelog/2013_02_13/o1_mf_1_6_2x3bbqym_.arc 
157     1    7       A 13-FEB-13
        Name: /orcva/PROD/archivelog/2013_02_13/o1_mf_1_7_2x3w2cvs_.arc
164     1    8       A 13-FEB-13
        Name: /orcva/PROD/archivelog/2013_02_13/o1_mf_1_8_2x3w40vr_.arc 
171     1    9       A 13-FEB-13
        Name: /orcva/PROD/archivelog/2013_02_13/o1_mf_1_9_2x3w8pf7_.arc
318     1    10      A 13-FEB-13
        Name: /orcva/PROD/archivelog/2013_02_13/o1_mf_1_10_2x3zx6d9_.arc 
330     1    11      A 13-FEB-13
        Name: /orcva/PROD/archivelog/2013_02_13/o1_mf_1_11_2x403wco_.arc
448     1    12      A 13-FEB-13
        Name: /orcva/PROD/archivelog/2013_02_13/o1_mf_1_12_2x40wn6x_.arc 
455     1    13      A 13-FEB-13
        Name: /orcva/PROD/archivelog/2013_02_13/o1_mf_1_13_2x412s3m_.arc
583     1    14      A 13-FEB-13
        Name: /orcva/PROD/archivelog/2013_02_13/o1_mf_1_14_2x428p9d_.ar 
638     1    15      A 13-FEB-13
        Name: /orcva/PROD/archivelog/2013_02_13/o1_mf_1_15_2x42f0gj_.arc
 
Do you really want to delete the above objects (enter YES or NO)?

Example 2-78 Forcing the Deletion of a Backup Set

The following example attempts to delete the backup set copy with tag weekly_bkup:

RMAN> DELETE NOPROMPT BACKUPSET TAG weekly_bkup;

RMAN displays a warning because the repository shows the backup set as available, but the object is not actually available on the media:

List of Backup Pieces
BP Key  BS Key  Pc# Cp# Status      Device Type Piece Name
------- ------- --- --- ----------- ----------- ----------
809     806     1   1   AVAILABLE   SBT_TAPE    0ri9uu08_1_1
 
RMAN-06207: WARNING: 1 objects could not be deleted for SBT_TAPE channel(s) due
RMAN-06208:          to mismatched status.  Use CROSSCHECK command to fix status
RMAN-06210: List of Mismatched objects
RMAN-06211: ==========================
RMAN-06212:   Object Type   Filename/Handle
RMAN-06213: --------------- ---------------------------------------------------
RMAN-06214: Backup Piece    0ri9uu08_1_1

The following command forces RMAN to delete the backup set (sample output included):

RMAN> DELETE FORCE NOPROMPT BACKUPSET TAG weekly_bkup;

using channel ORA_SBT_TAPE_1
using channel ORA_DISK_1
 
List of Backup Pieces
BP Key  BS Key  Pc# Cp# Status      Device Type Piece Name
------- ------- --- --- ----------- ----------- ----------
809     806     1   1   AVAILABLE   SBT_TAPE    0ri9uu08_1_1
deleted backup piece
backup piece handle=0ri9uu08_1_1 RECID=26 STAMP=614430728
Deleted 1 objects