Using Rman to restore a control file

The default backup format for control files is:
C-iiiiiiiiii-yyyymmdd-qq

which
C: Indicates a control file
IIIIIIIIII: Indicates dbid
YYYYMMDD: Time stamp for backup
Qq:16 binary serial number, starting from 00, maximum value FF

Using the fast recovery area or recovery catalog
1. Restore the control file from an automated backup
rman> restore controlfile from Autobackup;

2. Restore the control file from the specified backup slice
rman> restore Controlfile from '/tmp/piece_name ';

3. Restore the control files from the most recently available control file backup
rman> restore Controlfile;

If you are not using fast recovery area or recovery catalog, set the dbid before you restore the control file
4. Using the default backup in $oracle_home/dbs
Rman> set dbid=xxxxxxxx;
rman> restore controlfile from Autobackup;

5. The default is to recover from the default backup for the last 7 days, or you can specify the number of days
Rman> set dbid=xxxxxxxx;
rman> restore Controlfile from Autobackup maxdays 20;

6. Restore based on the sequence of automatic backups
Rman> set dbid=xxxxxxxx;
rman> restore Controlfile from Autobackup maxseq 20;

7. From a non-default backup PATH environment
Rman> set dbid=xxxxxxxx;
rman> set controlfile autobackup format for device type disk to '/tmp/%f ';
rman> restore controlfile from Autobackup;

8. Restore from a specified sub-division
Rman> set dbid=xxxxxxxxx;
rman> restore Controlfile from '/tmp/c-1140771490-20080502-03 ';

9. Restore the control file to a temporary directory, and then use the duplicate command to restore to the specified location and name based on the parameter control_files
Rman> set dbid=xxxxxxxxx;
rman> restore Controlfile from '/tmp/c-1140771490-2008050203 ' to '/tmp/control.tmp ';
Rman> replicate controlfile from '/tmp/control.tmp ';

10. Restore based on point in time
rman> restore Controlfile from autobackup until Time "to_date (' Jan 14:00:00 ', ' MON DD YYYY HH24:MI:SS ')";

Using Rman to restore a control file