Realizing this isn’t strictly a TOAD question, but you have “connections”…
Using the Quest SQL optimizer 8.1 for a poorly performing query… I started it up to see if it could do anything with a poorly performing query I’ve been puzzling over. It analyzed the query, came up with a ton of alternatives and started
testing. I notice that in the old “Auto Optimize” it didn’t seem to test them in any recognizable order, but in 8.1 it seems to be testing in the order they were generated, even though many early alternatives had costs in the millions higher and some later
alternates had lower cost. Is there a way to control the order it tests in? I couldn’t find one, or at least didn’t recognize anything.
Another tuning question: I know “cost” isn’t as meaningful an indicator as it used to be – sometimes high costs can be faster than low costs and vice versa, “it depends”, and sometimes you just have to test it, hence the auto optimizer,
but is “cost” even a meaningful yard stick anymore? Sometimes an awful looking explain plan blazes and forcing a plan that looks good performs poorly. I guess the question is – “What’s up with that?” (said in a very Jerry Seinfeld-ish voice)
IT Systems Analyst