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Using Data Recovery Advisor

The recovery proccss bcgins when you cither suspect or discover a failurc. You can discovcr failures in many ways, including crror messages, alerts, tracę files, and health checks. You can thcn usc Data Recovery Advisor to gain information and advice about failures and repair them automatically.

This section describcs a sccnario in which you use Data Recovcry Advisor to repair a corruptcd błock.

To use the Oracle advised recovery strategy to automatically repair failures:

1.    Connect RMAN to the targct database as described in "Connecting to the Target Database" on page 9-9.

2.    List all the failures know to the Data Recovery Advisor by running the following command:

LIST FAILURE;

List of Database Failures

Failure ID Priority Status Time Detected Summary 142 HIGH OPEN 23-APR-07 One or morę non-system datafiles are missing

101 HIGH OPEN 23-APR-07 Datafile 1: */diskl/oradata/prod/ systemOl.dbf' contains one or morę corrupt blocks

Whcrever possible, RMAN consolidates failures whilc displaying the result of the LIST FAILURE command. Forexample, if a data file contains multiple błock failures, the LIST FAILURE command consolidates and displays the repair options.

3.    If you suspcct that some failures that havc not been automatically diagnosed by the database exist, then chcck for corrupt blocks and missing data files by using the following command:

VALIDATE DATABASE;

If a problem is detected during the validation. thcn RMAN triggers the cxccution of a failurc assessment

4.    Determine repair options, both automatic and manuał, by using the following command:

ADVISE FAILURE;

5.    Fix the failures by using the following command:

REPAIR FAILURE;

Automated repairs are performed by the Data Recovery Advisor. In certain cases, such as when no backups exist for a lost control file, the only repair option possible is the manuał option.