Flash Recovery Area (FRA)

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Sometimes the Flash Recovery Area (FRA) is full and the Oracle DBA wants to know what is it’s usage, size and the list of occupants (archives, RMAN backups pieces or image copies, flashback logs).

To Enable  or Disable the FRA, it’s in another post here.

-- Use (MB) of 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;

-- FRA Occupants
SELECT * FROM V$FLASH_RECOVERY_AREA_USAGE;

-- Location and size of the FRA
show parameter db_recovery_file_dest

-- Size, usage, Reclaimable space used 
SELECT 
  ROUND((A.SPACE_LIMIT / 1024 / 1024 / 1024), 2) AS FLASH_IN_GB, 
  ROUND((A.SPACE_USED / 1024 / 1024 / 1024), 2) AS FLASH_USED_IN_GB, 
  ROUND((A.SPACE_RECLAIMABLE / 1024 / 1024 / 1024), 2) AS FLASH_RECLAIMABLE_GB,
  SUM(B.PERCENT_SPACE_USED)  AS PERCENT_OF_SPACE_USED
FROM 
  V$RECOVERY_FILE_DEST A,
  V$FLASH_RECOVERY_AREA_USAGE B
GROUP BY
  SPACE_LIMIT, 
  SPACE_USED , 
  SPACE_RECLAIMABLE ;

-- After that you can resize the FRA with:
-- ALTER SYSTEM SET db_recovery_file_dest_size=xxG;

-- Or change the FRA to a new location (new archives will be created to this new location):
-- ALTER SYSTEM SET DB_RECOVERY_FILE_DEST='/u....';

FLASH RECOVERY AREA architecture

It is important to monitor regularly space usage in the fast recovery area. The Oracle DBA must make sure that the FRA is large enough to contain backups and other recovery-related files.

If the PERCENT_FULL value (V$RECOVERY_FILE_DEST) is frequently close to 100% after several recent backups; consider allocating more space for your flash recovery area or decrease the retention time of your backups.

Oracle Database provides two views to monitor fast recovery area space usage, V$RECOVERY_FILE_DEST and V$RECOVERY_AREA_USAGE.

In a RAC infrastructure, the FRA is shared shared among all of the instances of an Oracle RAC database. It’s located in a shared storage area and on an Oracle ASM disk group.

A best practice is to be generous on FRA size!

Compatibility: Oracle 18c, 12c, 11g, 10g
Author: Vincent FENOLL – Oracle DBA Montreal

Summary
Article Name
Flash Recovery Area (FRA) usage, size and list of occupants
Description
The Oracle Flash Recovery Area (FRA) also known as the Fast Recover Area. Usage of this area must be monitored regularly to avoid a lack of space.
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