After upgrading from PowerCenter 8.6.1 HotFix 3 or later, you can warm start CDC sessions to restart the sessions from the point of interruption.
After upgrading from an earlier release to PowerCenter 8.6.1 HotFix 3 or later, you must cold start CDC. Before you cold start a session, you must establish the restart point for the session to ensure that it restarts from the point of interruption.