From: Jim Nasby <Jim.Nasby@BlueTreble.com>
To: Matthew Lunnon <mlunnon@rwa-net.co.uk>
To: pgsql-performance@postgresql.org
Subject: Re: Performance difference between Slon master and slave
Date: Mon, 14 Dec 2015 11:49:57 -0600
Message-ID: <566F0145.30707@BlueTreble.com> (raw)
In-Reply-To: <566EF984.5070404@rwa-net.co.uk>
References: <566EF984.5070404@rwa-net.co.uk>
List-Unsubscribe: <mailto:majordomo@postgresql.org?body=unsub%20pgsql-performance>
On 12/14/15 11:16 AM, Matthew Lunnon wrote:
> Inspecting the execution plan shows that there are some differences, for
> example, the slave is using a HashAggregate when the master is simply
> grouping. There also seems to be a difference with the ordering of the
> sub plans.
Have you tried analyzing the tables on the slave?
Also, keep in mind that the first time you access rows on a Slony slave
after they're replicated Postgres will need to write hint bits out,
which will take some time. But that's clearly not the issue here.
--
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
Data in Trouble? Get it in Treble! http://BlueTreble.com
--
Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance
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: Jim.Nasby@BlueTreble.com, mlunnon@rwa-net.co.uk
Subject: Re: Performance difference between Slon master and slave
In-Reply-To: <566F0145.30707@BlueTreble.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