On Apr 13, 2011, at 6:19 PM, Tomas Vondra <tv@xxxxxxxx> wrote: > Yes, I've had some lectures on non-linear programming so I'm aware that > this won't work if the cost function has multiple extremes (walleys / > hills etc.) but I somehow suppose that's not the case of cost estimates. I think that supposition might turn out to be incorrect, though. Probably what will happen on simple queries is that a small change will make no difference, and a large enough change will cause a plan change. On complex queries it will approach continuous variation but why shouldn't there be local minima? ...Robert -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
