Database Switchover and Failover on DR

Switchover

Convert primary database to standby

Ensure that the last redo data transmitted from the primary database was applied on the standby database

SQL>select sequence#,applied from v$archived_log;

Check whether the primary is ready for switch.

SQL>select switchover_status from v$database;

If this query returns "TO STANDBY", then the environment is ready to switch. If it returns "SESSIONS ACTIVE", then the switch command should be used with the 'session shutdown' option.

SQL>connect / as sysdba;
SQL>alter database commit to switchover to physical standby with session shutdown;

Shutdown and mount primary database for standby database

SQL>shutdown immediate;
SQL>startup nomount;
SQL>alter database mount standby database;
SQL>ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;

Verify the switchover status on new standby database

SQL>select switchover_status from v$database;

Above Query should return a value 'TO PRIMARY'

Check the Database role after switch

SQL>select database_role from v$database;

 
On the original standby database issue the following commands.

Convert standby database to primary

SQL>connect / as sysdba;
SQL>alter database commit to switchover to primary with session shutdown;

Shutdown and Startup old standby database as primary

SQL>SHUTDOWN IMMEDIATE;
SQL>STARTUP;

Check the Database role after switch

SQL>select database_role from v$database;

Failover

If the primary database is not available the standby database can be activated as a primary database using the following statements.

SQL>ALTER DATABASE RECOVER MANAGED STANDBY DATABASE FINISH;
SQL>ALTER DATABASE ACTIVATE STANDBY DATABASE;