From: Vincent de Phily <vincent.dephily@mobile-devices.fr>
To: French, Martin <frenchm@cromwell.co.uk>
Cc: pgsql-general@postgresql.org
Cc: pgsql-performance@postgresql.org
Subject: Re: [PERFORM] DELETE taking too much memory
Date: Fri, 08 Jul 2011 11:20:14 +0200
Message-ID: <6960221.CJCJgSSb5M@moltowork> (raw)
In-Reply-To: <81976671721DF04B9DCA6ECD87941A402B31E830@roundway.Cromwell-tools.co.uk>
References: <CAHdkwt5b=g_Nj0mogB-8u62U9wEB1KdCbPiBkJKGJyjM4q=FvQ@mail.gmail.com>
<81976671721DF04B9DCA6ECD87941A402B31E830@roundway.Cromwell-tools.co.uk>
On Thursday 07 July 2011 19:54:08 French, Martin wrote:
> How up to date are the statistics for the tables in question?
>
> What value do you have for effective cache size?
>
> My guess would be that planner thinks the method it is using is right
> either for its current row number estimations, or the amount of memory
> it thinks it has to play with.
Not very up to date I'm afraid (as shown by the low estimate of deleted rows).
Table t2 has been insert-only since its re-creation (that's another story),
while t1 is your classic insert-many, update-recent.
We haven't tweaked effective cache size yet, it's on the TODO... like many
other things :/
--
Vincent de Phily
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To: pgsql-performance@postgresql.org
Cc: vincent.dephily@mobile-devices.fr, frenchm@cromwell.co.uk, pgsql-general@postgresql.org
Subject: Re: [PERFORM] DELETE taking too much memory
In-Reply-To: <6960221.CJCJgSSb5M@moltowork>
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