From: Richard Huxton <dev@archonet.com>
To: Brian Choate <brianc@nimblefish.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Poor performance of delete by primary key
Date: Tue, 06 Sep 2005 16:51:05 +0100
Message-ID: <431DBAE9.3060205@archonet.com> (raw)
In-Reply-To: <2F9239F5E316C54688FDA9814FF045D6EADACC@EXCHANGE.sf.nimblefish.com>
References: <2F9239F5E316C54688FDA9814FF045D6EADACC@EXCHANGE.sf.nimblefish.com>
Brian Choate wrote:
> Hello,
>
> We are seeing a very strange behavior from postgres. For one of our
> very common tasks we have to delete records from a table of around
> 500,000 rows. The delete is by id which is the primary key. It seems
> to be consistently taking around 10 minutes to preform. This is
> totally out of line with the rest of the performance of the database.
> Any ideas on what might be going on?
Well, it sounds like *something* isn't using an index. You say that all
your FK's are indexed, but that's something worth checking. Also keep an
eye out for type conflicts.
If the system is otherwise idle, it might be worthwhile to compare
before and after values of pg_stat* (user-tables and user-indexes).
--
Richard Huxton
Archonet Ltd
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To: pgsql-performance@postgresql.org
Cc: dev@archonet.com, brianc@nimblefish.com
Subject: Re: Poor performance of delete by primary key
In-Reply-To: <431DBAE9.3060205@archonet.com>
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