Database Software

Can somone explain me how the space reclaimable is calculted in FRA in standby database. Oracle deletes the files automatically when FRA is full. Is it something FRA will cleared when the space used reaches 3000 gb in our case.

Previously we set 2000GB , FRA files are not deleted and our standby database was not applying the logs and it got hang. So we increase the FRA size to 3000 gb .It works fine now.

I am not clear why FRA is not cleared automatically. Can somone explain me how it works. and how files are getting deleted.

select name, space_limit/1024/1024/1024 space_limit_gb, space_used/1024/1024/1024 space_used_gb, SPACE_RECLAIMABLE/1024/1024/1024, NUMBER_OF_FILES from V$RECOVERY_FILE_DEST;

NAME SPACE_LIMIT_GB SPACE_USED_GB SPACE_RECLAIMABLE/1024/1024/1024 NUMBER_OF_FILES
-------------------- -------------- ------------- -------------------------------- ---------------
+ORA_FSRA1_DG 3000 2045.23459 22.7674656 1307

SQL> SELECT * FROM V$FLASH_RECOVERY_AREA_USAGE;

FILE_TYPE PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES
------------------------------------ ------------------ ------------------------- ---------------
CONTROLFILE 0 0 0
ONLINELOG 0 0 0
ARCHIVELOG .85 .83 201
BACKUPPIECE .01 0 1
IMAGECOPY 0 0 0
FLASHBACKLOG 67.26 0 1104