DB2® Universal Database™ for OS/390™ v7.1 Application Certification Guide

Tuning Guidelines

The following guidelines should be considered in developing an overall approach to performance tuning:

• Remember the law of diminishing returns: Your greatest performance benefits usually come from your initial efforts. Further changes generally produce smaller and smaller benefits and require greater effort.

• Do not tune just for the sake of tuning: Tune to relieve identified constraints. If you tune resources that are not the primary cause of performance problems, this can have little or no effect on response time until you have relieved the major constraints, and it can actually make subsequent tuning work more difficult. If there is any significant improvement potential, it lies in improving the performance of the resources ...