From: Steinar H. Gunderson <sgunderson@bigfoot.com>
To: Fernando Lujan <fernando.lujan@mandic.com.br>
Cc: pgsql-performance@postgresql.org
Subject: Re: Sequence Scan vs. Index scan
Date: Tue, 21 Mar 2006 19:17:32 +0100
Message-ID: <20060321181732.GA16124@uio.no> (raw)
In-Reply-To: <44204107.3040708@mandic.com.br>
References: <44204107.3040708@mandic.com.br>
On Tue, Mar 21, 2006 at 03:08:07PM -0300, Fernando Lujan wrote:
> I'm trying to figure out when Sequence Scan is better than Index Scan. I
> just want to know this because I disabled the sequence scan in
> postgresql and receive a better result. :)
That is a very broad question, and you're introducing somewhat of a false
choice since you're talking about joins (a join can be solved by more methods
than just "sequential scan" or not).
Could you please paste the exact query you're using, with EXPLAIN ANALYZE for
both the case with and without sequential scans?
/* Steinar */
--
Homepage: http://www.sesse.net/
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: sgunderson@bigfoot.com, fernando.lujan@mandic.com.br
Subject: Re: Sequence Scan vs. Index scan
In-Reply-To: <20060321181732.GA16124@uio.no>
* 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