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Re: bigint index not used

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Shiar <shiar(at)shiar(dot)org>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: bigint index not used
Date: 2004-03-26 23:15:01
Message-ID: 28354.1080342901@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-performance
Shiar <shiar(at)shiar(dot)org> writes:
>> EXPLAIN ANALYZE SELECT id FROM userinfo WHERE icq <> '0';
>  Seq Scan on userinfo  (cost=0.00..47355.90 rows=849244 width=4) (actual time=0.563..1222.963 rows=48797 loops=1)
>    Filter: (icq <> 0::bigint)
>  Total runtime: 1258.703 ms

The rows estimate is way off, which might or might not have much to do
with the issue, but it's surely suspicious.

> We're running PostgreSQL 7.4.1 on a Debian/Linux 2.4 system with 4GB RAM and a
> fast SCSI RAID array, with settings:

Update to 7.4.2 and follow the procedure in the release notes about
fixing pg_statistic; that may make things better.  int8 columns are
vulnerable to the statistic misalignment bug.

			regards, tom lane

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