Re: Damn slow query

Magnus Naeslund(f) wrote:
> Joe Conway <mail(at)joeconway(dot)com> wrote:
> > "IN (subselect)" is notoriously slow (in fact it is an FAQ). Can you
> > rewrite this as:
> >
>
> ...
>
> Stephan Szabo <sszabo(at)megazone23(dot)bigpanda(dot)com> wrote:
> > Per FAQ suggestion, try something like
>
> ...
>
> Thanks alot, below are the results on your suggestions, quite an
> dramatic differance (but this is another box, faster, and running 7.3b2
> so the 45 minutes doesn't hold here, but it took more than 10 minutes
> before i stopped the original query).
>
> Is this an todo item, or should every user figure this out (yeah i know
> i should have read the FAQ when it went so totally bad).
> The NOT IN it seems quite natural here, but then again, i don't think as
> the db as you do :)

We already have a TODO item:

* Allow Subplans to use efficient joins(hash, merge) with upper variable

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