Re: More Praise for 7.4RC2

Actually, in your case it's probably the new optimisation regarding the use
of IN (subquery). They're now optimised to the same lavel as EXISTS IIRC.

On Wed, Nov 12, 2003 at 05:46:23PM -0800, Reece Hart wrote:
> On Wed, 2003-11-12 at 09:04, jake johnson wrote:
>
> > I also posted about the performance increase of 7.4, but I think that
> > much of the difference you're seeing (because it's such a large
> > difference) is probably due to the cleanliness of a newly restored
> > database from backup.
>
>
> I agree that this seems likely, except that the 7.3.4 database is
> vacuumed nightly, and analyzed periodically. And about a week ago I
> reclustered on the index intended to most facilitate this select.
> Furthermore, merely hardcoding the subselect result achieves a
> tremendous improvement (which was the workaround I used). So, I'm pretty
> sure that it's not a vacuum, index use, or cleanliness issue.
>
> I also meant to add in my original post that the system is a dual 2.4G
> xeon with 4GB of RAM.
>
> -Reece
>
>
>
> --
> Reece Hart, http://www.in-machina.com/~reece/, GPG:0x25EC91A0 0xD178AAF9

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Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
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