Doing it Right the First Time

This chapter assumes the most common type of tuning environment, in which you're called in to tune up an existing system. You'll have some sorts of constraints placed upon your tuning activities depending upon your environment. If, by some freak of chance, you are tuning a production database before it actually goes production, you are in the rare position of being able to do it correctly the first time

If you can interject tuning issues early into the development process, you'll avoid many of the difficulties of tuning an active production system. The key to doing the development properly is to test at very high volumes and to resolve the tuning issues before the system goes into production. This is a lot more work and requires a lot more time than less rigorous testing does. It often requires a larger development system, one at least as large as a typical production system. Of course, your eventual production system can be the development system before it goes production. This is in many ways an ideal situation. Early development is done on the development machine. Volume testing should be done on the production machine prior to placing it in production.

Generating enough client load for testing a typical large database system is always a challenge. It often makes sense to combine your volume testing with some training or client acceptance procedure. While you're testing volume on the database, the trainees or client-side testers are generating volume for your testing. This "real" volume is quite valuable for testing purposes, since real users develop ways to crash systems that developers would never find by themselves. This real volume can be combined with workload generated by automated testing programs and with batch-processing, should the production system do batch processing. The idea is to simulate real volume as much as possible and for as long as possible.

This is an ideal way to move a new system into production. In many cases a system is rushed into production for revenue or other competitive reasons before being adequately tuned.