How to Enable Active Data Guard Option

Active Data Guard

If you want to run the Redo Apply Process and at the same time, open the standby database in read-only mode, you will have to go for Active Data Guard option. This is not possible in a normal Data Guard database (Physical Standby). Remember that, Active Data Guard needs additional licenses and additional cost. So, please check with your Oracle representative before going for this option.

Steps to Enable Active Data Guard Option

1. Cancel The Redo Apply Process

SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;

2. Shutdown and start the database in Mount Mode
SQL> SHUTDOWN IMMEDIATE

SQL> STARTUP MOUNT

3. Open the database in Read-Only Mode
(** If you do not want use the Active Data Guard option, then you do not have to execute the next Step. However, remember that, the redo apply will be disabled and real-time query can not be used)

SQL> ALTER DATABASE OPEN;

4. Start the Redo Apply. (Executing this Step will enable the Active Data Guard Option)

SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT;

5. Now that the standby is in real-time query mode (the standby is open in read-only
mode and Redo Apply is active), the V$DATABASE.OPEN_MODE column changes to
indicate the following:

SQL> SELECT open_mode FROM V$DATABASE;

OPEN_MODE
--------------------

READ ONLY WITH APPLY