One last note on the Data Recovery Advisor: if you know that you have had a failure and that it is not critical (e.g., a data file missing from a tablespace that is no longer used), then use the CHANGE FAILURE command to alter the priority of a failure. In this example, there is a missing data file that belongs to a noncritical tablespace.

First, obtain the failure priority via the LIST FAILURE command:

RMAN> list failure;

Here is some sample output:

Failure ID Priority Status          Time Detected Summary

5                  HIGH        OPEN          12-JUN-28       One or more non-system datafiles are missing

Next, change the priority from HIGH to LOW with the CHANGE FAILURE command:

RMAN> change failure 5 priority low;

You will be prompted to confirm that you really do want to change the priority:

Do you really want to change the above failures (enter YES or NO)?

If you do want to change the priority, then type YES, and press the Enter key. If you run the LIST FAILURE command again, you will see that the priority has now been changed to LOW:

RMAN> list failure low;

Complete Recovery

The term complete recovery means you can restore all transactions that were committed before a failure occurred. Complete recovery does not mean you are restoring and recovering all data files in your database.

For instance, you are performing a complete recovery if you have a media failure with one data file or even one data block, and you restore and recover the one data file or block.

For complete recovery, the following conditions must be true:

•     Your database is in archivelog mode.

•     You have a good baseline backup of the data files that have experienced media failure.

•     You have any required redo that has been generated since the last backup.

•     All archive redo logs start from the point at which the last backup began.

•     Any incremental backups that RMAN can use for recovery are available.

•     Online redo logs that contain transactions that have not yet been archived are available.

If you have experienced a media failure and you have the required files to perform a complete recovery, then you can restore and recover your database.

You can determine which files RMAN will use for restore and recovery before you actually perform the restore and recovery. You can also instruct RMAN to verify the integrity of the backup files that will be used for the restore and recovery.