Re: index is not used

i was surprised a few weeks ago by this effect.
it seems postgres uses sequential scans for queries when a huge number of
affected rows is expected.
i have read somewhere that it would be slower to use an index in this case.

greetingz

Thilo Hille
resourcery GbR.
Habsburgerstr. 11
79104 Freiburg
Tel.: 0761-4567807
Fax.: 0761-4567805
thilo(at)resourcery(dot)de

----- Original Message -----
From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: mila boldareva <pierro(at)dds(dot)nl>
Cc: <pgsql-novice(at)postgresql(dot)org>
Sent: Tuesday, August 20, 2002 4:50 PM
Subject: Re: [NOVICE] index is not used

> mila boldareva <pierro(at)dds(dot)nl> writes:
> > But the indices are not used, even when I added a separate index on
> > field1 !
>
> Have you run ANALYZE (or VACUUM ANALYZE) on that table?
>
> regards, tom lane
>
> ---------------------------(end of broadcast)---------------------------
> TIP 1: subscribe and unsubscribe commands go to majordomo(at)postgresql(dot)org
>