On Apr 13, 2011, at 6:19 PM, Tomas Vondra <tv(at)fuzzy(dot)cz> 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