fast recovery area tips

Up through Oracle 11g R1, the Oracle Flash Recovery Area (FRA) was the name of one of the basic components of the RMAN environment.

The FRA is essentially a disk location for the storage of files related to the recovery process.  These files in the FRA are managed by Oracle and RMAN automatically.  Files that could be found in the FRA include:

• RMAN backups
• control file
• logs
  • online redo log copies
  • archived redo logs
  • flashback logs

Using an FRA to automate the management of backup-related files can greatly simplify the administration of the database by providing automatic space management for files related to backup and recovery.  Otherwise, the DBA has to manually manage the space, which can be challenging because the components that are writing the different backup and recovery-related files are each unaware of the other and are ignorant to the size of the files the other is creating.

Here is a query to see the size of the FRA:

set lines 100
col name format a60

select
   name,
  floor(space_limit / 1024 / 1024) "Size MB",
  ceil(space_used / 1024 / 1024) "Used MB",
from
   v$recovery_file_dest
order by
   name;

 During creation, the FRA is given a disk location and an upper limit for space allowed for storage of the associated backup and recovery files.  The DBA also establishes a retention policy.  RMAN then automatically keeps the backups and any archived redo logs needed for complete recovery as are required to satisfy the policy.  When files are no longer needed for the established retention policy, they can be deleted as RMAN needs space for new files.

In Oracle 11g R2, the FRA has been renamed from the Flash Recovery Area to the Fast Recovery Area.  The description of the two in Oracle's RMAN documentation is unchanged other than the name, so DBA already using or planning to establish an FRA should be comforted that FRA=FRA.

Additional information on Flash (and Fast) Recovery Area is available at the following:

• Oracle Backing Up the Fast Recovery Area

• Archived redo logs & fast recovery area

• Oracle Resource Manager fast recovery area enhancements

• Oracle Concepts - configure fast recovery area

• Oracle fast recovery area & Flashback Database

Also check HERE for additional notes on:

• FRA

• Flash Recovery Area

• Fast Recovery Area

For more information about Backup and Recovery using RMAN and Data Pump, check out Kamran Agayev Agamehdi's excellent book Oracle Backup & Recovery: Expert secrets for using RMAN and Data Pump.