Oracle Dataguard Switchover

Oracle Dataguard Switchover steps

1. Initiate the switchover on the primary database PRIM:
SQL>connect / as sysdba
SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL STANDBY WITH SESSION SHUTDOWN;

2. After step 1 finishes, Switch the original physical standby db STAN to primary role;
Open another prompt and connect to SQLPLUS:
SQL>connect / as sysdba
SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY;

3. Immediately after issuing command in step 2, shut down and restart the former primary instance PRIM:
SQL>SHUTDOWN IMMEDIATE;
SQL>STARTUP MOUNT;

4. After step 3 completes:
- If you are using Oracle Database 10g release 1, you will have to Shut down and restart the new primary database STAN.
SQL>SHUTDOWN IMMEDIATE;
SQL>STARTUP;

- If you are using Oracle Database 10g release 2, you can open the new Primary database STAN:
SQL>ALTER DATABASE OPEN;

STAN is now transitioned to the primary database role.

5. On the new primary database STAN, perform a SWITCH LOGFILE to start sending redo data to the standby database PRIM.
SQL>ALTER SYSTEM SWITCH LOGFILE;