From: Ragnar <gnari@hive.is>
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 13:03:26 +0000
Message-ID: <1140699807.5728.42.camel@localhost.localdomain> (raw)
In-Reply-To: <43FDAC27.7050305@profiling-company.de>
References: <43FDAC27.7050305@profiling-company.de>
On fim, 2006-02-23 at 13:35 +0100, 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;
>
> A prepending "EXPLAIN" to the statement reveals a seq scan:
>
> EXPLAIN SELECT * FROM table WHERE id = 600000;
>
> "Seq Scan on table (cost=0.00..15946.48 rows=2 width=74)"
> " Filter: (id = 600000)"
> I tried a full vacuum and a reindex, but had no effect. Why is
> PostgreSQL not using the created index?
try one of:
SELECT * FROM table WHERE id = '600000';
SELECT * FROM table WHERE id = 600000::int8;
PostgreSQL 8+
gnari
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To: pgsql-performance@postgresql.org
Cc: gnari@hive.is, kjeld.peters@profiling-company.de
Subject: Re: Created Index is not used
In-Reply-To: <1140699807.5728.42.camel@localhost.localdomain>
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