From: Dave Dutcher <dave@tridecap.com>
To: vincent.moreau@leroymerlin.fr
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 08:24:37 -0500
Message-ID: <010401c76572$f33d33a0$2e00a8c0@tridecap.com> (raw)
In-Reply-To: <45F698F4.8030601@leroymerlin.fr>
> From: pgsql-performance-owner@postgresql.org
> [mailto:pgsql-performance-owner@postgresql.org] On Behalf Of
> vincent.moreau@leroymerlin.fr
> Subject: Re: [PERFORM] Execution plan changed after upgrade
> from 7.3.9 to 8.2.3
>
> The following did not change anything in the execution plan
>
> ALTER TABLE lm05_t_tarif_panneau ALTER COLUMN lrg_min SET
> STATISTICS 1000
> ALTER TABLE lm05_t_tarif_panneau ALTER COLUMN lrg_max SET
> STATISTICS 1000
> ANALYZE lm05_t_tarif_panneau
>
> I was able to improve response time by creating indexes, but I would
> like to avoid changing the database structure because it is not
> maintained by ourseleves, but by the third party vendor.
I would actually try increasing the statistics on table
lm05_t_couleur_panneau columns ht_min, ht_max, cod_aspect, and
cod_gamme_panneau. Because I think the planner is thrown off because the
sequential scan on lm05_t_couleur_panneau returns 280 rows when it expects
1. Maybe to start you could just SET default_statistics_target=1000,
analyze everything, and see if that makes any difference.
Dave
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To: pgsql-performance@postgresql.org
Cc: dave@tridecap.com, vincent.moreau@leroymerlin.fr
Subject: Re: Execution plan changed after upgrade from 7.3.9 to 8.2.3
In-Reply-To: <010401c76572$f33d33a0$2e00a8c0@tridecap.com>
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