In situations where you need to force the primary server to shut down (for example, if you are replacing the computer it is running on), you can force the mirror server to become the primary server when it would not otherwise take ownership of the database by using the ALTER DATABASE statement.

You must connect to the utility database on the mirror database server to use this feature. You can connect to the utility database by specifying -su option in the command to start the mirroring servers. The following command forces the mirror server for the database mymirroreddb.db to become the primary server:

ALTER DATABASE mymirroreddb FORCE START;

The FORCE START clause forces a database server that is currently acting as the mirror server to take ownership of the database. This statement can be executed from within a procedure or event, and must be executed while connected to the utility database on the mirror server. See Connecting to the utility database.

If you want to force a failover from the primary to the mirror, you can:

• stop the primary server
• execute ALTER DATABASE SET PARTNER FAILOVER while connected to the database on the primary server (this statement causes the primary server to restart the database and become the mirror)

See also

• ALTER DATABASE statement