From: Gregory Stark <stark@enterprisedb.com>
To: Joshua D. Drake <jd@commandprompt.com>
Cc: Campbell\, Lance <lance@uiuc.edu>
Cc: pgsql-performance@postgresql.org
Subject: Re: Suggestions on an update query
Date: Sat, 27 Oct 2007 03:04:47 +0100
Message-ID: <87odel1feo.fsf@oxford.xeocode.com> (raw)
In-Reply-To: <20071026141547.70c9c1e0@scratch>
References: <B10E6810AC2A2F4EA7550D072CDE8760197DC6@SAB-FENWICK.sab.uiuc.edu>
<B10E6810AC2A2F4EA7550D072CDE8760197DC7@SAB-FENWICK.sab.uiuc.edu>
<20071026141547.70c9c1e0@scratch>
"Joshua D. Drake" <jd@commandprompt.com> writes:
> On Fri, 26 Oct 2007 15:31:44 -0500
> "Campbell, Lance" <lance@uiuc.edu> wrote:
>
>> I forgot to include an additional parameter I am using in
>> Postgresql.conf:
>>
>
> O.k. first, just to get it out of the way (and then I will try and
> help). Please do not top post, it makes replying contextually very
> difficult.
>
>> PostgreSql version 8.2.4
>>
>> Memory = 8 Gig
>>
>> CPUs 1 dual core Zeon running at 3.0
>>
>
> O.k. first you might be grinding through your 20 checkpoint segments
> but in reality what I think is happening is you are doing foreign key
> checks against all of it and slowing things down.
If you're going to berate someone about top-posting perhaps you should attach
your own commentary to relevant bits of context :P
But the original post didn't include any foreign key constraints. I suspect
you've guessed it right though. In fact I suspect what's happening is he
doesn't have an index on the referencing column so the foreign key checks are
doing sequential scans of.
--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com
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To: pgsql-performance@postgresql.org
Cc: stark@enterprisedb.com, jd@commandprompt.com, lance@uiuc.edu
Subject: Re: Suggestions on an update query
In-Reply-To: <87odel1feo.fsf@oxford.xeocode.com>
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