Compatibility, maintenance, and upgrading These topics provide information about Db2® Query Monitor compatibility, maintenance, and upgrading. CompatibilityEnsure that Db2 Query Monitor components are compatible with your environment.Maintenance - APARs and PTFsDb2 Query Monitor requires that maintenance (APARs and PTFs) be applied. Before applying maintenance, exit all instances of the Db2 Query Monitor. If your site is configured to use CAE components, shut down all instances of your CAE agents and CAE servers.UpgradingYou can upgrade Db2 Query Monitor 3.3.0 to version 3.4.0. You can also maintain multiple product versions concurrently.Reverting the Query Monitor subsystem to a previous versionFollow these steps to revert from the current version of the Query Monitor subsystem to a previous version.Removing PTFsYou can remove individual PTFs or fixtests from Db2 Query Monitor. Removing CAE componentsFollow these steps to remove CAE components.Removing backup CAE serversFollow these steps to remove the primary CAE server and any backup CAE servers.Parent topic: Installation and maintenance