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$database; NAME OPEN_MODE --------- -------------------- PRODDB READ ONLY WITH APPLY SQL> select process,status,sequence# from v$managed_standby; PROCESS STATUS SEQUENCE# --------- ------------ ---------- 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
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