Re: aggregate functions, COUNT

* Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> [02-10-01 18:02]:
> Stephan Szabo <sszabo(at)megazone23(dot)bigpanda(dot)com> writes:
> > I think you could use EXISTS for that,
> > select EXISTS (<query>); should give a true/false on whether the
> > query returned any rows. I'm not sure if it stops after one row
> > or not, but if it doesn't you can add a limit 1 to the query.
>
> Yes it does stop after one row; and furthermore, the planner knows to
> generate a fast-start plan for it. (Or at least it's supposed to
> ... hmm, this seems to be broken in current sources ...) Anyway,
> there's no need for LIMIT 1 inside an EXISTS, because the planner
> assumes that automatically.

Thank you muchly, I did some profiling and SELECT EXISTS is indeed
exactly what I wanted.

-Kevin Way

--
Kevin Way <kevin(dot)way(at)overtone(dot)org>
http://www.overtone.org/