From: Markus Schaber <schabi@logix-tt.com>
To: Kjeld Peters <kjeld.peters@profiling-company.de>
Cc: pgsql-performance@postgresql.org
Subject: Re: Created Index is not used
Date: Thu, 23 Feb 2006 13:46:02 +0100
Message-ID: <43FDAE8A.60805@logix-tt.com> (raw)
In-Reply-To: <43FDAC27.7050305@profiling-company.de>
References: <43FDAC27.7050305@profiling-company.de>
Hi, Kjeld,
Kjeld Peters wrote:
> Select and update statements are quite slow on a large table with more
> than 600,000 rows. The table consists of 11 columns (nothing special).
> The column "id" (int8) is primary key and has a btree index on it.
>
> The following select statement takes nearly 500ms:
>
> SELECT * FROM table WHERE id = 600000;
Known issue which is fixed in 8.X servers, postgreSQL sees your 600000
as int4 literal and does not grasp that the int8 index works for it.
SELECT * FROM table WHERE id = 600000::int8;
should do it.
> SELECT version();
> "PostgreSQL 7.4.2 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 3.3.3
> (SuSE Linux)"
Btw, you should update to 7.4.12, there are importand bug fixes and it
is upgradable "in place", without dumping and reloading the database.
HTH,
Markus
--
Markus Schaber | Logical Tracking&Tracing International AG
Dipl. Inf. | Software Development GIS
Fight against software patents in EU! www.ffii.org www.nosoftwarepatents.org
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To: pgsql-performance@postgresql.org
Cc: schabi@logix-tt.com, kjeld.peters@profiling-company.de
Subject: Re: Created Index is not used
In-Reply-To: <43FDAE8A.60805@logix-tt.com>
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