From: | Ragnar <gnari(at)hive(dot)is> |
---|---|
To: | Denis Gasparin <denis(at)edistar(dot)com> |
Cc: | pgsql-general(at)postgresql(dot)org |
Subject: | Re: Query that does not use indexes |
Date: | 2007-03-28 10:11:42 |
Message-ID: | 1175076702.1153.80.camel@localhost.localdomain |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general |
On þri, 2007-03-27 at 12:54 +0200, Denis Gasparin wrote:
> I have a query that performs a multiple join between four tables and
> that doesn't use the defined indexes.
> If I set enable_seqscan to off, the query obviously uses the indexes and
> it is considerable faster than normal planned execution with
> enable_seqscan=true.
a few things you might try:
fiddle with random_page_cost
make sure effective_cache_size is set to a realistic value
increase statistics target on critical columns, like
ORDER.ORDER_DATE and join columns
(and re-analyze)
possibly get change the cast in your where clause:
ORDER.ORDER_DATE::date between '2007-03-01' and '2007-03-27'
to
ORDER.ORDER_DATE between '2007-03-01'::timestamp
and '2007-03-27'::timestamp
gnari
From | Date | Subject | |
---|---|---|---|
Next Message | Dmitry Koterov | 2007-03-28 10:12:43 | Re: Strange behaviour under heavy load |
Previous Message | Stephane Bortzmeyer | 2007-03-28 10:07:25 | [ANNOUNCE] echoping 6, with a PostgreSQL plugin |