Databases Reference
In-Depth Information
If you configure a tape channel, RMAN will use both the (preconfigured) disk and the tape channels to delete the
backups and copies.
How It Works
When you issue the
delete backup
command, RMAN does the following:
1.
Removes the physical file from the backup media
2.
Marks the status of the deleted backup in the control file as deleted
3.
Deletes the rows pertaining to the deleted backup from the recovery catalog repository,
which is actually stored in database tables, if you are using a recovery catalog and are
actually connected to it while deleting the backup
If you issue the
delete backup
command, you may sometimes get the RMAN prompt back right away without
any messages about deleted backups. However, that doesn't mean RMAN has deleted all backups. This actually
means RMAN didn't find any backups to delete. Here's an example:
RMAN> delete backup;
using channel ORA_DISK_1
RMAN>
If you issue the simple
delete
command, without specifying the
force
option, the deletion mechanism works in
the following manner under different circumstances:
•
If the status of the object is listed as available in the repository but the physical copy isn't
found on the media, RMAN doesn't delete the object or alter the repository status.
•
If the status is listed as unavailable in the repository, RMAN deletes the object if it exists and
removes the repository record for the object.
•
If the object has the expired status and RMAN can't find the object on the media, RMAN
doesn't delete the object or update its repository status.
Here are some options you can use with the
delete
command when deleting backups:
delete force
: Deletes the specified files whether they actually exist on media or not and
removes their records from the RMAN repository as well
delete expired
: Deletes only those files marked
expired
pursuant to the issuance of the
crosscheck
command.
delete obsolete
: Deletes data file backups and copies and the archived redo logs and log
backups that are recorded as
obsolete
in the RMAN repository
Instead of using the basic
delete backup
command, you can also use the alternative deletion command,
backup ...
delete [all] input
, to first make a backup of and then delete the input files (source files) of backup sets, data file
copies, and archived redo logs. Typically you use the
backup ... delete
command to back up the source files to tape
and then delete them after a successful backup. We show you how to use the
backup ... delete
command in the
next recipe, where we focus on deleting archived redo logs.
