Re: Horribly slow hash join - Mailing list pgsql-performance

From Bruno Wolff III
Subject Re: Horribly slow hash join
Date
Msg-id 20040419031554.GA1881@wolff.to
Whole thread Raw
In response to Re: Horribly slow hash join  (Dennis Bjorklund <db@zigo.dhs.org>)
Responses Re: Horribly slow hash join  (Dennis Bjorklund <db@zigo.dhs.org>)
List pgsql-performance
On Sun, Apr 18, 2004 at 18:27:09 +0200,
  Dennis Bjorklund <db@zigo.dhs.org> wrote:
> On Sun, 18 Apr 2004, Tom Lane wrote:
>
> > > What do you mean? int8 is supported on all platformas
> >
> > No it isn't.
>
> So on platforms where it isn't you would use int4 as the biggest int then.
> I don't really see that as a problem. As long as you calculate the hash on
> the biggest int on that platform it should work.

Another option would be to put the numbers into two int4s. For int4 or
smaller types one of these would be zero. int8s would be split between
the two. The hash function would then be defined on the two int4s.

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