How To Enable Flash Recovery Area In Oracle Database
The flash recovery area(FRA) is an Oracle-managed destination( either FILE SYSTEM or ASM ) for centralized backup and recovery files. It simplifies the 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 auto backups
— Datafile and control file copies
— Backup pieces
— Foreign archived redo log
Below are the steps for enabling flash recovery area.
DB_RECOVERY_FILE_DEST_SIZE and DB_RECOVERY_FILE_DEST initial parameters are required for enabling FRA.
DB_RECOVERY_FILE_DEST_SIZE -> It is the disk quota size for the flash recovery area.
DB_RECOVERY_FILE_DEST – > This initialization parameter is a valid destination for the Flash Recovery Area. It can be a directory, file system, or ASM disk group.
NOTE : DB_RECOVERY_FILE_DEST_SIZE must be set before DB_RECOVERY_FILE_DEST.
1. Check whether FRA is enabled or not.
SQL> show parameter db_recovery_file
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string
db_recovery_file_dest_size big integer 0
SQL> select * from V$RECOVERY_FILE_DEST;
no rows selected
2. Enable FRA.
SQL> alter system set db_recovery_file_dest_size=20G scope=both;
SQL> alter system set db_recovery_file_dest='/u01/oradata/FRA' scope=both;
SQL> show parameter db_recovery_file
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string /u01/oradata/FRA
db_recovery_file_dest_size big integer 20G
select * from V$RECOVERY_FILE_DEST;
NAME SPACE_LIMIT SPACE_USED SPACE_RECLAIMABLE NUMBER_OF_FILES CON_ID
-------------------------------------- ----------- ---------- ----------------- --------------- ----------
/u01/oradata/FRA 2.1475E+10 0 0 0 0
Now FRA has been enabled.
How to make archivelog destination same as flash recovery area:
SQL> alter system set log_archive_dest_1='LOCATION=USE_DB_RECOVERY_FILE_DEST' scope=both;
System altered.
SQL> archive log list
Database log mode Archive Mode
Automatic archival Enabled
Archive destination USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence 816
Next log sequence to archive 818
Current log sequence 818
SQL> alter system switch logfile;
select * from v$flash_recovery_area_usage
FILE_TYPE PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES CON_ID
----------------------- ------------------ ------------------------- --------------- ----------
CONTROL FILE 0 0 0 0
REDO LOG 0 0 0 0
ARCHIVED LOG .01 0 1 0
BACKUP PIECE 0 0 0 0
IMAGE COPY 0 0 0 0
FLASHBACK LOG .49 0 2 0
FOREIGN ARCHIVED LOG 0 0 0 0
AUXILIARY DATAFILE COPY 0 0 0 0
FOR RAC:
For RAC database, DB_RECOVERY_FILE_DEST_SIZE and DB_RECOVERY_FILE_DEST parameter must be same across all the instances. So it is recommended to put FRA on ASM DISKS.
SQL> alter system set db_recovery_file_dest_size=20G scope=both sid='*';
SQL> alter system set db_recovery_file_dest='+FRADG' scope=both sid='*';
