RMAN Restore of Incremental Backups (SAP Library - SAP Database Guide: Oracle (BC-DB-ORA-DBA))

RMAN Restore of Incremental Backups

Use

If you perform an Oracle database backup with the Oracle Recovery Manager (RMAN), you must generally also restore it with RMAN. However, this does not apply to backups made to disk. SAPDBA supports the following:

Database reset to an incremental backup

Partial restore followed by a recovery using incremental backups.

If required, you can continue to recover the database by importing the offline redo log files.

Prerequisites

In contrast to the BRRESTORE restore process (without RMAN) where the database has to be closed, the database must be mounted for an RMAN restore.

Activities

The procedure for resetting the entire database to an incremental backup, or to a point in time before the database failure (database reset, point-in-time recovery, disaster recovery) is as follows:

Prerequisite: The database is closed.

You restore the control file, and if needed, the online redo log files from the last incremental backup, using BRRESTORE (that is, not using RMAN).

Prerequisite: The database is mounted.

You perform a:

Restore of the full backup (level 0) with RMAN
Restore of the last incremental backup with RMAN

You restore offline redo log files with BRRESTORE.

Prerequisite: The database is mounted.

You apply the offline redo log files to the database to reset the data to the required point in time.

If only some of the files are corrupt, perhaps due to a media error, then you only need to restore those files from the full backup and then restore the last incremental backup. RMAN then makes the changes to the files automatically, restoring them to the last incremental backup. The current database is recovered by importing the redo log files.

Caution

If the database has been restored since the last full backup (level 0), then you cannot use it as a reference for the next incremental backup. Be sure to start a full database backup immediately after the database has been successfully recovered.