BACKUP OFFLINE CATALOGO

Keeping a Long-Term Backup: Example

If you configure a retention policy, then you may want to exclude specified backups from this policy. For example, you may want to archive a consistent backup of the database once a year to serve as a historical record. This long-term backups does not function as a backup that you may perform recovery on, but an archived snapshot of data at a particular time.
To exempt a backup from the retention policy, specify the KEEP option on the BACKUP command. You can also specify LOGS or NOLOGS to indicate whether RMAN should save archived logs for possible recovery of this backup. If you specify NOLOGS, then the backup must be consistent.
This example keeps the backup of the database indefinitely and does not save archived logs needed to recover it:

RMAN> SHUTDOWN IMMEDIATE;
RMAN> STARTUP MOUNT;  # put database in consistent state
RMAN> BACKUP DATABASE KEEP FOREVER NOLOGS
              TAG 'db_archive_1'; # make long-term consistent backup

# mark backup as unavailable in the repository so that RMAN does not attempt to
# restore it unless explicitly specified on the RESTORE command
RMAN> CHANGE BACKUP TAG 'db_archive_1' UNAVAILABLE;
RMAN> SQL 'ALTER DATABASE OPEN';