Upgrade Guide for DB2 UDB for z/OS and OS/390 > Database and UI Upgrade Planning > Planning Your Upgrade >

Testing Before a Production Upgrade

Careful testing is critical for a successful upgrade. In particular, the production upgrade must be thoroughly tested to avoid data-specific issues and gain the best possible performance during your upgrade.

CAUTION:  Do not go live on Siebel 7.7 without exhaustive performance testing.