Does that query really return 9420 rows ? If so, a sequential scan is
probably better/faster than an index scan..
-Mitch
----- Original Message -----
From: <ryan@paymentalliance.net>
To: <pgsql-general@postgresql.org>
Sent: Thursday, May 10, 2001 9:22 AM
Subject: Re: Query not using index
> I vacuum every half hour! Here is the output from EXPLAIN:
>
> NOTICE: QUERY PLAN:
>
> Seq Scan on pa_shopping_cart (cost=0.00..7237.94 rows=9420 width=296)
>
> EXPLAIN
>
> Thanks!
>
>
> On Thu, 10 May 2001 18:19:16 +0000 (UTC),
> sszabo@megazone23.bigpanda.com (Stephan Szabo) wrote:
>
> >
> >Have you vacuum analyzed recently and what does
> >explain show for the query?
> >
> >On Thu, 10 May 2001 ryan@paymentalliance.net wrote:
> >
> >> Here's the query:
> >>
> >> SELECT
> >> cart_row_id
> >> FROM
> >> pa_shopping_cart
> >> WHERE
> >> order_id = 20;
> >> [ ... ]
> >> There is an index on:
> >> just order_id
> >> just order_id and cart_row_id
> >> and a PK on cart row_id
> >>
> >> I don't understand why it's not using one of these indexes!
> >> Please post your responses to the group - my email is down.
> >
> >
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