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Rewinding a Database Using Oracle Flashback Database

Unlikc thc othcr flashback fcatures, Oracle Flashback Database operates at a physical level. When you usc Flashback Database, your currcnt data files revert to their contents at a previous time. The result is similar to database point-in-timc recovery, but Flashback Database can be much faster bccause it does not rcquirc you to restore and recovcr data files. Also, Flashback Database requires limited application of redo data as compared to media recovery.

Flashback Database uses flashback logs to access previous versions of data blocks and also uses some data in the archived redo log files. To have thc option of using Flashback Database to repair your database, you must have configured thc database to generate flashback logs as explained in "Configuring Recovery Settings" on page 9-10. To perform a Flashback Database operation:

1.    Connect RMAN to the target database as describcd in "Connecting to thc Target Database" on page 9-9.

2.    Identify the desired SCN, restore point, or point in time to which the flashback database must be performed. This example rewinds the database to a specified point in time.

3.    Shut down the database consistently, ensure that it is not opened by any instance, and then mount the database.

SHUTDOWN IMMEDIATE;

STARTUP MOUNT;

4.    Flash back the database to the desired time.

In this example, you need to flashback the entire database to the time specified in the TIME clause.

FLASHBACK DATABASE to TIME "TO_DATE('03/20/12'MM/DD/YY')";

5.    Open the database read-only and run some queries to verify the database contents. The following command opens the database in read-only modę:

ALTER DATABASE OPEN READ ONLY;

6.    Aftcr confirming that the statc of thc database is as expected. make thc database available for updates by opening it with the RESETLOGS option.