Q&As: Block Media Recovery


(Q) What is Block Media Recovery?

Recovery of specified blocks within a data file
RMAN> RECOVER ... BLOCK
Leaves the affected datafiles ONLINE and recovers only the damaged/corrupted data blocks.


$ rman
RMAN> connect target /
connected to target database: ORCL11G (DBID=123456789)

RMAN> recover datafile 2 block 13;
...

     (optionally)
RMAN> recover … 
        From backupset …
        Exclude flashback log

     (To recover ALL blocks logged in V$DATABASE_BLOCK_CORRUPTION)
RMAN> recover corruption list;

Q&As: Fast Recovery Area (II)


(Q) What initialization parameters are used to configure a Fast Recovery Area?

  • DB_RECOVERY_FILE_DEST - specifies default location for fast recovery area.
  • DB_RECOVERY_FILE_DEST_SIZE - specifies (in bytes) the hard limit on the total space to be used by target database recovery files created in the fast recovery area
  • (optional) DB_FLASHBACK_RETENTION_TARGET -Specifies the upper limit (minutes) on how far back in time the database may be flashed back.


(Q) Can you configure the Fast Recovery Area on an ASM disk group?

  • Yes


(Q) How large should you configure the Fast Recovery Area?


  • At an ABSOLUTE MINIMUM, it should be large enough to containt the archived redo logs not yet on tape.
  • Scenario:
    • If you use incrementally updated backups and set the backup retention policy to REDUNDANCY 1, you can determine the size of the fast recovery area as below:



Q&As: Backup with Recovery Manager



(Q) Which statements about using RMAN to perform backups are correct?


  • ( ) You CAN perform incremental backups with RMAN
  • ( ) RMAN detects corrupt blocks and logs in V$DATABASE_BLOCK_CORRUPTION
  • ( ) Automatically establishes name and locations of all files to be backed up
  • ( ) Backups are recorded in the CONTROL FILE, which is the main repository of RMAN metadata.
  • ( ) Optionally, you CAN store backup metadata in a recovery catalog, which should be a schema in a database different of the one backed up.
  • ( ) The primary storage for RMAN repository information for a database is always in the control file of the database. 
  • ( ) RMAN supports proxy copy, a feature that allows a media manager to manage completely the transfer of data between disk and backup media
  • ( ) RMAN backups init parameter file
  • ( ) RMAN DOES NOT backup password and networking files.
  • ( ) RMAN supports a platform-independent language for backups