Fast Recovery Area

Fast Recovery Area è un directory fisica nel server o in automatic storage management diskgroup che viene gestito da Oracle per salvare i backup e i file di recovery.La FRA viene configurata in automatico durante l'installazione.

In genere contiene:
- archivelogs
- flashback database change logs
- backup sets prodotti da RMAN.

I parametri associati alla FRA sono:
db_recovery_file_dest
db_recovery_file_dest_size

Verifichaimo se esite; accedere come root container:

SQL> show con_name

CON_NAME
------------------------------
CDB$ROOT

SQL> show parameter db_reco

NAME TYPE VALUE
------------------------------------ ----------- ----------------
db_recovery_file_dest string

db_recovery_file_dest_size     big integer      0

Come si abilita?

Creare un direcotry su file system

[oracle@test oracle]$ mkdir /u01/app/oracle/fast_recovery_area

Accedere come root container:

SQL>  alter system set DB_RECOVERY_FILE_DEST_SIZE=5G;

SQL>  alter system set DB_RECOVERY_FILE_DEST='/u01/app/oracle/fast_recovery_area';

Questa operazione scrive nel spfile, infatti se si visualizzano i parametri di prima compare questo:

SQL> show parameter db_reco;

NAME                                 TYPE                  VALUE

------------------------------------ ----------- --------------------------------------------------------

db_recovery_file_dest                string           /u01/app/oracle/fast_recovery_area

db_recovery_file_dest_size      big integer     5G

Maintaining the Fast Recovery Area 

--Fast Recovery Area Space Consumption

$ sqlplus / as sysdba 

SQL> SELECT SPACE_LIMIT/1024/1024 AS SPACE_LIMIT_MB, 

SPACE_USED/1024/1024 SPACE_USED_MB, 

SPACE_RECLAIMABLE/1024/1024 SPACE_RECLAIMABLE_MB, 

NUMBER_OF_FILES 

FROM V$RECOVERY_FILE_DEST; 

SQL> SELECT NAME

     FROM V$RECOVERY_FILE_DEST; 

--Fast Recovery Area Space Usage Based on Type of Files

SQL> SELECT FILE_TYPE, NUMBER_OF_FILES,

 PERCENT_SPACE_USED AS PER_USED, 

PERCENT_SPACE_RECLAIMABLE AS PER_RECLAIM 

FROM V$RECOVERY_AREA_USAGE;