RMAN backup test without downtime

As a responsible DBA, periodically checking the database restore and recovery is a must to ensure the disaster recovery plan works. Unfortunately, most of backup restore and recovery procedures require scheduled downtime either at database level or at tablespace level. For system with high availability requirement, such scheduled downtime is hard to come by. In order to test the reliability of restore/recovery of such system, it is possible to carry out the procedure very close to full scale restore/recovery without take database system offline.

Option 1: RMAN validate:

RMAN can validate the database restore at database level, backupset level, datafile level, and data block level. The RMAN validate checks the RMAN backup file is accessible and no physical and/or logical corruption. The following RMAN commands are used to perform validation.
• VALIDATE …
• BACKUP ... VALIDATE
• RESTORE ... VALIDATE
For example: “VALIDATE DATABASE;” checks if current database files have intrablock corruption. “BACKUP DATABASE VALIDATE;” creates the backupset of the database and check for block level corruption for online database files. “RESTORE DATABASE VALIDATE” performs the database restore without actually writing the database file to disk. VALIDATE can be used for backup validation as well, such as “VALIDATE BACKUPSET ;” DBA can check the backupset using “RESTORE … VALIDATE” similarly by “SET UNTIL TIME …” right after the backupset is created. In short, both “VALIDATE …” and “RESTORE … VALIDATE” can be used for RMAN backup validation. RMAN VALIDAE could not detect interblock corruption of datafile and that is for dbverify.

Option2: Restore to new location

You can complete the whole nine yard of restore without database/tablespace downtime. Use “SET UNTIL TIME …” to select the time scale of the restore and “SET NEWNAME FOR …” to select the location of the restore. For example:
RUN
{
set until time "to_date('2011-07-15:19:00:00','YYYY-MM-DD:hh24:mi:ss')";
set newname for datafile '/nas01/app/oracle/oradata/orcl/users01.dbf' to '/tmp/users01.dbf';
RESTORE datafile 4;
}