Databases Reference
In-Depth Information
The
delete obsolete
command shown here will delete all backups deemed obsolete per your configured
backup retention policy.
Not
■
the
delete obsolete
command relies only on the backup retention policy in force. it doesn't consider the
configured archived redo log deletion policy in effect to determine which archived redo logs are obsolete. the
delete
archivelog all
command, on the other hand, relies entirely on the configured archived redo log deletion policy.
The following examples show how to use either the
redundancy
or
recovery window
clause to delete backups
that are deemed obsolete according to a retention policy you have configured:
RMAN> delete obsolete redundancy = 2;
The command shown here deletes backups that exceed the redundancy requirement of 2:
RMAN> delete obsolete recovery window of 14 days;
The previous command deletes backups and the archived redo logs that aren't necessary to recover the database
to an arbitrary SCN within the past two weeks.
How It Works
Obsolete backups are any backups that you don't need to satisfy a configured retention policy. You may also delete
obsolete backups according to any retention policy you may specify as an option to the
delete obsolete
command.
The
delete obsolete
command will remove the deleted files from the backup media and mark those backups as
deleted in both the control file and the recovery catalog.
When deleting obsolete backups, it's important to understand how the
keep until
clause impacts how RMAN
deems a backup obsolete. No matter what
keep until
time you specify, RMAN will never consider a backup obsolete
if that backup is needed to satisfy any retention policy you might have configured. This applies to both a recovery
window-based and a redundancy-based retention policy. If you set the
keep until
time for some backups longer
than a configured retention policy interval, however, RMAN will retain those backups. Regardless of any configured
backup retention policy, a backup will be considered obsolete as soon as its
keep until
period expires, and the
delete obsolete
command will delete all such obsolete backups.
Changing the Status of an RMAN Backup Record
Problem
You have migrated some backups off-site and want to let RMAN know that those files aren't available to it.
Solution
Use the
change ... unavailable
command when you move backups off-site or can't find a backup for some reason.
Here's an example showing how you can change the status of a backup set to unavailable because you've temporarily
moved the backup set to a different location because of a lack of space on a disk:
RMAN> change backupset 10 unavailable;
