2 Replies Latest reply: Sep 20, 2010 9:16 AM by Vladimir Zakharychev RSS

    db_flashback_retention_target & flashback logs deletion question

    765173
      Hi, This is 11.2.0.1 Oracle database on Solaris 10.

      Even though db_flashback_retention_target is specified as 5040 (3.5 days), FRA is storing flashback logs for 6 days. There are no restore points or guaranteed restore points on this system.

      SQL> show parameter retention

      NAME TYPE VALUE
      ------------------------------------ ----------- ------------------------------
      db_flashback_retention_target integer 5040
      undo_retention integer 7200
      SQL>

      Just to let you know, RMAN retention policy is set to REDUNDANCY 3.

      Does oracle delete flashback logs when db_flashback_retention_target is met or it keeps them if there is space left and even though db_flashback_retention_target is met?
        • 1. Re: db_flashback_retention_target & flashback logs deletion question
          618702
          user12872633,

          I think those online documentations will help you;

          http://download.oracle.com/docs/cd/E11882_01/backup.112/e10642/rcmmaint.htm#BRADV89615
          http://download.oracle.com/docs/cd/E11882_01/backup.112/e10642/flashdb.htm#CFHJJHEC

          By the way, have you recently decreased the db_flashback_retention_target parameter's value?

          Regards.

          Ogan
          • 2. Re: db_flashback_retention_target & flashback logs deletion question
            Vladimir Zakharychev
            Yes, db_flashback_retention_target is actually just that - target minimum log retention time which Oracle will try to satisfy. If there is more space in the FRA available, Oracle will happily store more flashback logs than it needs to satisfy the target. There is no explicit way to delete flashback logs, they will eventually be deleted automatically as FRA fills up and Oracle will need to free some space in it. You can force this cleanup by lowering db_recovery_file_dest_size so that FRA will appear full and then setting it to original value after the cleanup is complete.

            Hth,
            Vladimir