From: Greg Smith <greg@2ndquadrant.com>
To: Aaron Turner <synfinatic@gmail.com>
Cc: pgsql-performance <pgsql-performance@postgresql.org>
Subject: Re: large dataset with write vs read clients
Date: Thu, 07 Oct 2010 17:47:07 -0400
Message-ID: <4CAE3FDB.1040909@2ndquadrant.com> (raw)
In-Reply-To: <AANLkTimNJc=0ffgRO_gO6Vsq06=aqBYXZouhbv0kBe-i@mail.gmail.com>
References: <AANLkTimNJc=0ffgRO_gO6Vsq06=aqBYXZouhbv0kBe-i@mail.gmail.com>
Aaron Turner wrote:
> Are newer PG versions more memory efficient?
>
Moving from PostgreSQL 8.1 to 8.3 or later should make everything you do
happen 2X to 3X faster, before even taking into account that you can
tune the later versions better too. See
http://suckit.blog.hu/2009/09/29/postgresql_history for a simple
comparison of how much performance jumped on both reads and writes in
the later versions than what you're running. Memory consumption will on
average decrease too, simply via the fact that queries start and finish
more quickly. Given an even workload, there will be less of them
running at a time on a newer version to keep up.
Given the size of your database, I'd advise you consider a migration to
a new version ASAP. 8.4 is a nice stable release at this point, that's
the one to consider moving to. The biggest single problem people
upgrading from 8.1 to 8.3 or later see is related to changes in how data
is cast between text and integer types; 1 doesn't equal '1' anymore is
the quick explanation of that. See
http://wiki.postgresql.org/wiki/Version_History for links to some notes
on that, as well as other good resources related to upgrading. This may
require small application changes to deal with.
Even not considering the performance increases, PostgreSQL 8.1 is due to
be dropped from active support potentially as early as next month:
http://wiki.postgresql.org/wiki/PostgreSQL_Release_Support_Policy
Also: PostgreSQL 8.1.3 has several known bugs that can lead to various
sorts of nasty data corruption. You should at least consider an
immediate upgrade to the latest release of that version, 8.1.22. Small
version number increases in PostgreSQL only consist of serious bug
fixes, not feature changes. See
http://www.postgresql.org/support/versioning for notes about the
project's standard for changes here, and how it feels about the risks of
running versions with known bugs in them vs. upgrading.
--
Greg Smith, 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
PostgreSQL Training, Services and Support www.2ndQuadrant.us
Author, "PostgreSQL 9.0 High Performance" Pre-ordering at:
https://www.packtpub.com/postgresql-9-0-high-performance/book
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: greg@2ndquadrant.com, synfinatic@gmail.com
Subject: Re: large dataset with write vs read clients
In-Reply-To: <4CAE3FDB.1040909@2ndquadrant.com>
* 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