The flash recovery area is an Oracle-managed directory, file system, or Automatic Storage Management disk group that provides a centralized disk location for backup and recovery files. All the files you need to completely recover a database from a media failure are part of the Flash Recovery Area. Oracle creates archived logs and flashback logs in the flash recovery area. RMAN can store its backup sets and image copies in the flash recovery area, and it uses it when restoring files during media recovery. The flash recovery area also acts as a disk cache for tape.

Flash recovery extends the functionality of Oracle Managed Files to all recovery related files (backup sets, image copies, and archived logs). Oracle Database automatically manages this storage, deleting files that are no longer needed. The user specifies only the location of a Flash Recovery Area, and the amount of disk space that Oracle is allowed to use for recovery related files. This feature is integrated with the 10G MMON feature, so that out of space conditions can be handled through the standard Oracle monitoring framework.

Periodically copying backups to tape frees space in the flash recovery area for other files. Oracle recommends that you enable a recovery area to simplify backup management.

The following recovery-related files are stored in the flash recovery area: 
— Current control file 
— Online redo logs
— Archived redo logs 
— Flashback logs 
— Control file autobackups 
— Datafile and control file copies 
— Backup pieces
— Foreign archived redo log ( An archived redo log received by a logical standby database for a LogMiner session.)

Configure FRA

If you did not specify a location for the fast recovery area during installation, the installation process automatically configures a fast recovery area in the Oracle base directory.

Oracle recommends, however, that the fast recovery area be located on a separate storage device from the database files.

Assume that you want to want to place the fast recovery area in the directory /u02/oracle/fra and you want its size to have an upper limit of 10 GB.

Specify the size of the fast recovery area using the following command

ALTER SYSTEM SET DB_RECOVERY_FILE_DEST_SIZE = 10G;

Specify the location of the fast recovery area using the following command:

ALTER SYSTEM SET DB_RECOVERY_FILE_DEST = '/oracle/fra';