From: vincent.moreau@leroymerlin.fr
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Michael Fuhr <mike@fuhr.org>
Cc: pgsql-performance@postgresql.org
Subject: Re: Execution plan changed after upgrade from 7.3.9 to 8.2.3
Date: Tue, 13 Mar 2007 16:46:34 +0100
Message-ID: <45F6C75A.4070407@leroymerlin.fr> (raw)
In-Reply-To: <2335.1173798373@sss.pgh.pa.us>
References: <45F65EA3.1030706@leroymerlin.fr>
<20070313101117.GA98241@winnie.fuhr.org>
<45F686FA.2090909@leroymerlin.fr>
<20070313130945.GB4490@alvh.no-ip.org>
<45F6A6F8.9090405@leroymerlin.fr>
<20070313134306.GC6715@alvh.no-ip.org>
<45F6AFA9.4020804@leroymerlin.fr>
<2335.1173798373@sss.pgh.pa.us>
Thanks for the advice Tom !
Setting enable_nestloop = off did improve the query a much better way
than setting enable_seqscan to off.
It does not screw the costs either (I had very odd costs with
enable_seqscan to off like this : Nested Loop
(cost=400001665.30..400002197.96 rows=1 width=96)
Is there a "performance risk" to have enable_nestloop = off for other
queries ?
If I had the choice, should I go for index creation for the specific
tables or should I tweak the optimizer with enable_nestloop = off ?
Thanks again to all of you for your help.
Best Regards,
Vincent
Tom Lane wrote:
> <vincent.moreau@leroymerlin.fr> writes:
>
>> I was able to improve response time by seting enable_seqscan to off
>>
>
> enable_nestloop = off would probably be a saner choice, at least for
> this particular query.
>
> regards, tom lane
>
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To: pgsql-performance@postgresql.org
Cc: vincent.moreau@leroymerlin.fr, tgl@sss.pgh.pa.us, mike@fuhr.org
Subject: Re: Execution plan changed after upgrade from 7.3.9 to 8.2.3
In-Reply-To: <45F6C75A.4070407@leroymerlin.fr>
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