DBID

 To restore the control file from an autobackup, the database must be in a NOMOUNT state. You need the database ID (DBID) to retrieve the autobackups. Your DBID should be recorded along with other basic information about your database. If you do not have a record of the DBID of your database, there are two places you can easily find it:

·From the formatted name of a control file autobackup.

·From a RMAN session log file. The DBID is displayed by the RMAN client when it starts up and connects to your database