The Data Recovery Advisor tool was introduced in Oracle Database 11g. In the event of a media failure, this tool will display the details of the failure, recommend corrective actions, and perform the recommended actions if you specify that it do so. It is like having another set of eyes to provide feedback when in a restore-and-recovery situation.

There are four modes to Data Recovery Advisor:

•     Listing failures

•     Suggesting corrective action

•     Running commands to repair failures

•     Changing the status of a failure

The Data Recovery Advisor is invoked from RMAN. You can think of the Data Recovery Advisor as a set of RMAN commands that can assist you when dealing with media failure.

Listing Failures

When using the Data Recovery Advisor, the LIST FAILURE command is used to display any issues with the data files, control files, or online redo logs:

RMAN> list failure;

If there are no detected failures, you will see a message indicating that there are no failures. Here is some sample output indicating that there may be an issue with a data file: List of Database Failures

Failure ID Priority Status          Time Detected Summary

6222            CRITICAL OPEN        12-JUN-23       System datafile 1: ‘/u01/dbfile/db23c/system01.dbf’ is missing

To display more information about the failure, use the DETAIL clause:

RMAN> list failure 6222 detail;

Here is the additional output for this example:

Impact: Database cannot be opened

With this type of failure, the prior output indicates that the database cannot be opened.

If you suspect there is a media failure, yet the Data Recovery Advisor is not reporting any issues, run the VALIDATE DATABASE command to verify that the database is intact.