Re: Index unused with OR?

> Unrelated to the question in hand - you complained about VACUUM not
> properly updating the stats. It seems to me you should use VACUUM ANALYZE
> for that to happen. Just vacuuming means elimination of old rows no longer
> used.
>
> Herouth

Thanks for your hint, the statistics got updated now with VACUUM
ANALYZE, but indexes aren't used anyway when combining indexed
columns with OR in the WHERE part:

w=> vacuum;
VACUUM
w=> vacuum analyze;
VACUUM
w=> explain select * from p where (m=29000) or (m=30000);
NOTICE: QUERY PLAN:

Seq Scan on p (cost=336.92 size=834 width=10)

EXPLAIN
w=>

Kind regards,
Olaf
--
Olaf Mittelstaedt - IuK - mittelstaedt(at)fh-ulm(dot)de
Fachhochschule Ulm Prittwitzstr. 10 89075 Ulm
Tel.: +49 (0)731-502-8220 Fax: -8270

Tertium non datur.