Active dataguard means, the standby database is open with read only mode, even when redo logs are getting applied in real time.

Below are the benefit of using active dataguard.

  • Reporting queries can be offloaded to standby database.
  • Physical block corruptions are repaired automatically either at primary or physical standby database.
  • RMAN backups can be initiated from standby , instead  of primary which will reduce cpu load from primary.
  • NOTE - To use active dataguard, you need additional license from oracle

    Let-s say we have a physical standby database which is in mount state. Implement below steps to enable active dataguard database.


    1. Cancel the media recovery on physical standby.

    SQL> alter database recover managed standby database cancel;

    2. Open the database[PHYSICAL STANDBY]

    SQL> alter database open;
    Database altered.

    3. Start media recovery with real-time log apply[PHYSICAL STANDBY]

    SQL> alter database recover managed standby database using current logfile disconnect from session;
    Database altered.

    4. Check the database status:[PHYSICAL STANDBY]

    SQL> select name,open_mode from v$database;
    --------- --------------------
    SQL> select process,status,sequence# from v$managed_standby;
    --------- ------------ ----------
    ARCH      CONNECTED             0
    ARCH      CONNECTED             0
    ARCH      CONNECTED             0
    ARCH      CONNECTED             0
    ARCH      CONNECTED             0
    RFS       IDLE                  0
    RFS       RECEIVING           510
    RFS       IDLE                  0
    RFS       IDLE               4178
    MRP0      APPLYING_LOG        510 --->>>>  MRP PROCESS 

    Now active dataguard has been enabled.

    dataguard DATAGUARD