From: Gerardo Herzig <gherzig@fmed.uba.ar>
To: pgsql-sql@postgresql.org
Subject: amount of join's and sequential access to the tables involved
Date: Wed, 11 Jan 2012 12:36:32 -0300
Message-ID: <1326296192.24629.12.camel@inca.fmed.uba.ar> (raw)
Hi all. Im working on a 'simple' query with 7, 8 left joins. After the
9nth join or so, explain analyze became to show the plan with many
tables being read in sequential fashion. Of course, this slows down the
query response in a factor on 10.
I can alter the order in wich the join's are appended, allways with the
same result.
So,it looks like a resources config situation.
Wich config variables are involved in the use of hash joins?
(I dont have access right now to the server running pg, so i cannot show
query plan nor pg configuration)
Thanks!
Gerardo
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-sql@postgresql.org
Cc: gherzig@fmed.uba.ar
Subject: Re: amount of join's and sequential access to the tables involved
In-Reply-To: <1326296192.24629.12.camel@inca.fmed.uba.ar>
* 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