FRA

From Oracle FAQ
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FRA (flash or fast recovery area) is a storage area (directory on disk or ASM diskgroup) that contains redo logs, control file, archived logs, backup pieces and copies, flashback logs and, in 11g, foreign archived logs. The flash recovery area was first introduced in Oracle 10g.

Configuration

To enable FRA for the database:

SQL> ALTER DATABASE FLASHBACK ON;

To disable for selected tablespaces:

SQL> ALTER TABLESPACE tbs_1 FLASHBACK OFF;

Related parameters that can to be set:

  • db_recovery_file_dest
  • db_recovery_file_dest_size
  • db_flashback_retention_target (optional, default is 1440 minutes or 1 day)

Benefits of an FRA

  • Quick recovery from backups stored on disk
  • Ability to flashback the database
  • Automate management of recovery related files (like archived logs)

The only drawback is that may require a lot of disk space (up to 2 or 3 times the size of the database).

Monitoring

To see if it's enabled:

SQL> SELECT flashback_on, log_mode FROM v$database;

The FRA can be monitored by selecting from the following views:

  • V_$FLASHBACK_DATABASE_STAT
  • V_$FLASHBACK_DATABASE_LOG
  • V_$FLASHBACK_DATABASE_LOGFILE

Also see

Glossary of Terms
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