Understand the Application
Before you can successfully tune a system, you have to understand the types of applications that run on it. We've gone into fairly extensive detail about the tuning differences between OLTP and DSS systems, and that should give you some general rules for tuning, but they are just general guidelines. Every system is different, and they all have different requirements. Don't just take for granted that you know how the system is being used. Check it out firsthand.
Understand not only what types of applications run, but also when they run and how long it takes. Be sure that you are aware of any processing windows, especially any hard windows that cannot be violated.
A good example was a major credit card processing application ...
Get Informix DBA Survival Guide, Second Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.