Re: Serious Flaws in 7.23's Optimizer - Not using indexes

We've found in similar circumstances in the past that the OPTCOMPIND setting change will partially solve things. Even better, we discovered that the usual drop and recreate indexes / update stats solved the problem. We also re-jiggled/deleted one of the clashing indexes that seemed to be confusing the optimiser. Incidentally, on that particular release (713 on DGUX) we found that upd stats drop distribs followed by upd stats high had a better result! ALAN COWAN <alan.cowan@autodesk.com> wrote in article <5sabkt$lk6@cssun.mathcs.emory.edu>... > In a nutshell: > The Optimizer does not usee indexes even if EVERY join is an indexed > field. > Lots of problems in other examples including every time I use EXISTS it > does a SEQUENTIAL search where an index is available. > Informix 5 did not have these problems. >