On Wed, 2006-02-15 at 16:51 -0500, Tom Lane wrote: > Gary Doades <gpd@xxxxxxxxxxxx> writes: > > Interestingly, if I don't delete the table after a run, but just drop > > and re-create the index repeatedly it stays a pretty consistent time, > > either repeatedly good or repeatedly bad! > > This is consistent with the theory of a data-dependent performance > problem in qsort. If you don't generate a fresh set of random test > data, then you get repeatable runtimes. With a new set of test data, > you might or might not hit the not-so-sweet-spot that we seem to have > detected. Agreed. Good analysis... Best Regards, Simon Riggs
