Database Reference
In-Depth Information
Complete Recovery
As discussed in Chapter 3, the term
complete recovery
means that you can restore all transactions that were committed
before a failure occurred.
Complete recovery
doesn't mean that 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, and you
restore and recover the one data file. 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 (if using).
•
Online redo logs that contain transactions that have not yet been archived are available.
If you've experienced a media failure, and you have the required files to perform a complete recovery, then you
can restore and recover your database.
Testing Restore and Recovery
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.
Previewing Backups Used for Recovery
Use the
RESTORE...PREVIEW
command to list the backups and archive redo log files that RMAN will use to restore and
recover database data files. The
RESTORE...PREVIEW
command does not actually restore any files. Rather, it lists the
backup files that will be used for a restore operation. This example previews in detail the backups required for restore
and recovery for the entire database:
RMAN> restore database preview;
You can also preview require backup files at a summarized level of detail:
RMAN> restore database preview summary;
Here is a snippet of the output:
List of Backups
===============
Key TY LV S Device Type Completion Time #Pieces #Copies Compress Tag
------- -- -- - ----------- --------------- ------- ------- -------- ---
12 B 0 A DISK 28-SEP-14 1 1 YES TAG20140928T110657
11 B 0 A DISK 28-SEP-14 1 1 YES TAG20140928T110657
