Re: Index isn't used during a join. - Mailing list pgsql-performance

From Michael Fuhr
Subject Re: Index isn't used during a join.
Date
Msg-id 20060111075655.GA51292@winnie.fuhr.org
Whole thread Raw
In response to Re: Index isn't used during a join.  (Robert Creager <Robert_Creager@LogicalChaos.org>)
Responses Re: Index isn't used during a join.  (Michael Fuhr <mike@fuhr.org>)
Re: Index isn't used during a join.  (Robert Creager <Robert_Creager@LogicalChaos.org>)
List pgsql-performance
On Tue, Jan 10, 2006 at 10:10:55PM -0700, Robert Creager wrote:
> The query is now correct, but still is slow because of lack of
> index usage.  I don't know how to structure the query correctly to
> use the index.

Have you tried adding restrictions on doy in the WHERE clause?
Something like this, I think:

WHERE ...
  AND doy >= EXTRACT(doy FROM now() - '24 hour'::interval)
  AND doy <= EXTRACT(doy FROM now())

Something else occurred to me: do you (or will you) have more than
one year of data?  If so then matching on doy could be problematic
unless you also check for the year, or unless you want to match
more than one year.

--
Michael Fuhr

pgsql-performance by date:

Previous
From: Ron
Date:
Subject: Re: help tuning queries on large database
Next
From: Andrea Arcangeli
Date:
Subject: Re: NOT LIKE much faster than LIKE?