Taking Over the Primary Database Role

A secondary database can take over the role of primary database at any time; for example, for scheduled maintenance where you want to move processing to a new location.

A takeover initiated from a secondary database is considered a hostile takeover. For more details about taking over the primary database role and about negotiated and hostile takeovers, see "SDS Takeover Operations", earlier in this chapter.

To take over the primary database role

1. Select the Initiate Takeover command in the Admin menu.

   The Initiate Takeover or Initiate Hostile Takeover command is enabled only when the secondary system is disconnected from the primary system.

   When accessed from a secondary database, this is displayed as the Initiate Hostile Takeover command. For more details, see "Taking Over of the Primary Database Role from a Secondary Database", later in this chapter.

   If you initiated this action from the primary database, the SDS Takeover dialog, shown in the following image, is then displayed.

   

2. In the combo box, select the secondary database that is to assume the primary database role.

3. If you want the takeover operation to have precedence over reader processes so that the takeover is forced if conflicts exist, select the Forced option button.

   By default, conditional takeovers are performed; that is, the takeover is performed only when there are no reader process conflicts. If reader or replay conflicts exist on the secondary database, the takeover operation is abandoned.

4. Click the OK button. Alternatively, click the Cancel button to abandon the takeover action.

The SDS Admin database view is then updated to reflect the role change when the next refresh action occurs.