From: Tom Lane <tgl@sss.pgh.pa.us>
To: Sami Dalouche <skoobi@free.fr>
Cc: pgsql-performance@postgresql.org
Subject: Re: Outer joins and Seq scans
Date: Sun, 28 Oct 2007 18:08:34 -0400
Message-ID: <8688.1193609314@sss.pgh.pa.us> (raw)
In-Reply-To: <1193606710.9008.12.camel@samlaptop>
References: <1193606710.9008.12.camel@samlaptop>
Sami Dalouche <skoobi@free.fr> writes:
> So, what could prevent postgrs from using the index ?
You've carefully withheld all the details that might let us guess.
If I had to guess anyway, I'd guess this is a pre-8.2 PG release
that doesn't know how to rearrange outer joins, but there are any
number of other possibilities.
If you want useful help on a query planning issue, you generally need
to provide
- the exact Postgres version
- full schema declaration of the relevant tables
- exact queries tested
- full EXPLAIN ANALYZE output
With less info than that, people are just shooting in the dark.
regards, tom lane
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, skoobi@free.fr
Subject: Re: Outer joins and Seq scans
In-Reply-To: <8688.1193609314@sss.pgh.pa.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox