Problem Description
Should you find yourself in a situation where a Data Guard Broker switchover to Standby has
failed and left your environment with 2 Physical Standby Databases, follow this simple
procedure to switch the failed switchover Standby Database back to Primary.
You may also see the following error from a DGMGRL "show configuration" command:
ORA-16816: incorrect database role
Solution
1. Logon (as sysdba) to the instance that was your Primary database instance before
the switchover.
2. Confirm the database role.
SQL> select database_role from v$database;
DATABASE_ROLE
----------------
PHYSICAL STANDBY
3. Shutdown the instance.
SQL> shutdown immediate;
4. Mount the database.
SQL> startup mount;
5. Cancel the MRP process. You will receive “ORA-16136: Managed Standby Recovery
not active” if it is not running, but you can ignore.
SQL> alter database recover managed standby database cancel;
6. Terminate the current switchover to Standby that never completed fully.
SQL> alter database recover managed standby database finish;
7. Now switchover to Primary.
SQL> alter database commit to switchover to primary with
session shutdown;
8. Open the database.
SQL> alter database open;
9. Confirm the database role.
SQL> select database_role from v$database;
DATABASE_ROLE
----------------
PRIMARY
Additional Steps
When attempting to open the Primary Database you may suffer the following error:
SQL> alter database open
*
ERROR at line 1:
ORA-16649: possible failover to another database prevents this
database being opened
In this case, before you can open the database, you must disable Data Guard Broker as
follows:
SQL> alter system set dg_broker_start=false scope=both
sid=’*’;
System altered.
SQL> alter database open;
Database altered.
Now re-install Data Guard Broker.
