Re: What affects performance?

OK, there've been all sorts of responses here which rightly don't attempt to sum things up in a nutshell. The real message is that there is no substitute for gaining an understanding of how the various components of the Informix DBMS work - the optimiser, the data engine... As any consultant worth his salt acknowledges, there are no quick fixes, no golden rules. You just have to know your stuff. The only rule I'd apply is, start from the application code / physical data design and work from there towards engine tuning and, last of all, hardware spec. *Never* **ever** the common knee-jerk reaction to go the other way around. For gaining that oh-so-important understanding, there are worse places to start than certain chapters (eg. 6, 7, 9 [from memory] ) of the "Guide to SQL : Tutorial". Therein lies the initial grounding in the concepts, albeit over-simplified in parts. akent@cix.compulink.co.uk (Andy Kent) ------------------------------------- 44 272 742815