8.3 Deleting Backups

8.3.1 Deleting Specified Backups

In general, use the DELETE command to remove backups that you do not want to retain. DELETE removes the physical files from the backup media, deletes the record of the backup from the recovery catalog (if RMAN is connected to a recovery catalog), and updates the records of these backups in the control file to status DELETED.

The DELETE command supports deleting several types of backups, including:

DELETE BACKUP (which deletes backup sets, proxy copies, and image copies), DELETE COPY (which deletes only image copies), or DELETE ARCHIVELOG as in these examples:

The DELETE command supports a wide range of options to identify backups to delete. For complete information about these options, see Oracle Database Backup and Recovery Reference. The following examples show many of the common ways to specify backups and archived logs to delete using theDELETE command:

• Deleting backups using primary keys from LIST output:

  DELETE BACKUPPIECE 101;
  
  

• Deleting backups by filename on disk:

  DELETE CONTROLFILECOPY '/tmp/control01.ctl';
  
  

• Deleting archived redo logs from disk:

  DELETE NOPROMPT ARCHIVELOG UNTIL SEQUENCE = 300;
  
  

• Deleting backups based on tags:

  DELETE BACKUP TAG='before_upgrade';
  
  

• Delete backups based on the objects backed up and the media or disk location where the backup is stored:

  DELETE BACKUP OF TABLESPACE users DEVICE TYPE sbt; # delete only from tape
  DELETE COPY OF CONTROLFILE LIKE '/tmp/%';  # 
  
  

• Delete all backups for this database recorded in the RMAN repository:

  DELETE BACKUP; 
  
  

• Delete backups and archived redo logs from disk based on whether they are backed up on tape:

  DELETE ARCHIVELOG ALL 
     BACKED UP 3 TIMES TO sbt; 
  
  

If you run RMAN interactively, then RMAN asks for confirmation before deleting any files. You can suppress these confirmations by using the NOPROMPT keyword with any form of the BACKUP command:

DELETE NOPROMPT ARCHIVELOG ALL; 
  

8.3.2 Deleting Expired RMAN Backups after CROSSCHECK

When the CROSSCHECK command is used to determine whether backups recorded in the repository still exist on disk or tape, if RMAN cannot locate the backups, then it updates their records in the RMAN repository to EXPIRED status. You can then use the DELETE EXPIRED command to remove records of expired backups from the RMAN repository. If the expired files still exist, then the DELETE EXPIRED command terminates with an error.

To delete expired repository records:

1. If you have not performed a crosscheck recently, then issue a CROSSCHECK command. For example, issue:

   CROSSCHECK BACKUP; # checks backup sets and copies on configured channels
   
   

2. Delete the expired backups. For example, issue:

   DELETE EXPIRED BACKUP;
   

8.3.3 Using DELETE FORCE With RMAN Backups

It is possible for the RMAN repository to indicate that an object has one status while the actual status of the object on the media is different. For example, the RMAN repository says that a backup set is AVAILABLE when it is in fact no longer present on disk or tape (or missing from the media manager's catalog of the contents of tapes or other backup media). If you attempt to delete the object, then you receive a warning such as the following:

RMAN-06207: WARNING: 1 objects could not be deleted for DISK channel(s) due
RMAN-06208:          to mismatched status.  Use CROSSCHECK command to fix status
List of Mismatched objects
==========================
  Object Type   Filename/Handle
--------------- ---------------------------------------------------
Backup Piece    0id270ud_1_1

If you use the DELETE command with the optional FORCE keyword, RMAN deletes the specified backups, but ignores any I/O errors, including those that occur when a backup is missing from disk or tape. It then updates the RMAN repository to reflect the fact that the backup is deleted, regardless of whether RMAN was able to delete the file or whether the file was already missing. For example:

DELETE FORCE NOPROMPT BACKUPSET TAG 'weekly_bkup';

8.3.4 Deleting Obsolete RMAN Backups Based on Retention Policies

The RMAN DELETE command supports an OBSOLETE option, which deletes backups that are obsolete, that is, no longer needed to satisfy specified recoverability requirements. You can delete files obsolete according to the configured default retention policy, or another retention policy that you specify as an option to the DELETE OBSOLETE command. As with other forms of the DELETE command, the files deleted are removed from backup media, deleted from the recovery catalog, and marked as DELETED in the control file.

If you specify the DELETE OBSOLETE command with no arguments, then RMAN deletes all obsolete backups defined by the currently configured retention policy For example:

DELETE OBSOLETE;

You can also use the REDUNDANCY or RECOVERY WINDOW clauses with DELETE to delete backups obsolete under a specific retention policy instead of the configured default:

DELETE OBSOLETE REDUNDANCY = 3;

DELETE OBSOLETE RECOVERY WINDOW OF 7 DAYS;