The changes in DB2® registry variables, configuration parameters, and database physical design characteristics can have an upgrade impact. Review these changes to manage the upgrade impact.
After upgrading your DB2 server, compare the values of your registry variables and configuration parameters to their values before upgrade. If you find any differences, take the time to understand them because they could alter the behavior or performance of your applications. However, consider carefully whether to disable any new functionality because it provides support for new resources needed by the database manager. You should disable new functionality only if you experience negative performance or unwanted behavior.
To manage DB2 server behavior changes: