Re: IN optimization in 7.2 ????? - Mailing list pgsql-general

hubert depesz lubaczewski wrote:
> On Mon, Feb 18, 2002 at 09:52:19AM -0500, Bruce Momjian wrote:
> > Not that I know of.
>
> strange. what could lead to this results then?
> i used to think that IN (SELECT ...) is the slowest possible way at all.
>
> depesz
>
> p.s. of course both select's use indices, and table is vacuumed

I have always wondered this too.  Seems IN evaluates the entire query
while EXISTS evaluates it for each row, or at least that is how I
understand it, so saying EXISTS is always faster may be wrong.
Comments?


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