Re: Admission Control

"Ross J. Reedstrom" <reedstrm@rice.edu> writes:
> Hmm, I'm suddenly struck by the idea of having a max_cost parameter,
> that refuses to run (or delays?) queries that have "too high" a cost.

That's been suggested before, and shot down on the grounds that the
planner's cost estimates are not trustworthy enough to rely on for
purposes of outright-failing a query.  If you didn't want random
unexpected failures, you'd have to set the limit so much higher than
your regular queries cost that it'd be pretty much useless.

Maybe it'd be all right if it were just used to delay launching the
query a bit, but I'm not entirely sure I see the point of that.
        regards, tom lane