Re: Out of Memory - 8.2.4 - Mailing list pgsql-general

From Alvaro Herrera
Subject Re: Out of Memory - 8.2.4
Date
Msg-id 20070830132710.GF5872@alvh.no-ip.org
Whole thread Raw
In response to Re: Out of Memory - 8.2.4  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Out of Memory - 8.2.4  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
Tom Lane escribió:
> Alvaro Herrera <alvherre@commandprompt.com> writes:
> > I'm not having much luck really.  I think the problem is that ANALYZE
> > stores reltuples as the number of live tuples, so if you delete a big
> > portion of a big table, then ANALYZE and then VACUUM, there's a huge
> > misestimation and extra index cleanup passes happen, which is a bad
> > thing.
>
> Yeah ... so just go with a constant estimate of say 200 deletable tuples
> per page?

How about we use a constant estimate using the average tuple width code?

--
Alvaro Herrera                 http://www.amazon.com/gp/registry/CTMLCN8V17R4
"In fact, the basic problem with Perl 5's subroutines is that they're not
crufty enough, so the cruft leaks out into user-defined code instead, by
the Conservation of Cruft Principle."  (Larry Wall, Apocalypse 6)

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