Skip site navigation (1) Skip section navigation (2)

Re: [GENERAL] Drupal and PostgreSQL - performance issues?

From: Greg Smith <gsmith(at)gregsmith(dot)com>
To: Simon Waters <simonw(at)zynet(dot)net>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: [GENERAL] Drupal and PostgreSQL - performance issues?
Date: 2008-10-13 21:21:27
Message-ID: Pine.GSO.4.64.0810131710090.26116@westnet.com (view raw or flat)
Thread:
Lists: pgsql-generalpgsql-performance
On Mon, 13 Oct 2008, Simon Waters wrote:

> One of our servers is fairly pressed for memory (some of the time). Is there
> any way to measure the amount of churn in the shared_buffers, as a way of
> demonstrating that more is needed (or at this moment more would help)?

If you wander to http://www.westnet.com/~gsmith/content/postgresql/ my 
"Inside the PostgreSQL Buffer Cache" presentation goes over this topic in 
extreme detail.

> Can I ask Postgres to tell me, or estimate, how much memory this table 
> would occupy if fully cached in memory?

http://wiki.postgresql.org/wiki/Disk_Usage gives an example showing all 
the biggest tables/indexes in your data, and links to an article giving 
examples of how to find the size of all sorts of things.  One of the 
queries in my presentation even shows you what % of each table is actually 
being cached by the dedicated database memory.

You also need to consider the OS buffer cache to get the full picture, 
which is a bit more complicated; 
http://www.kennygorman.com/wordpress/?p=250 gives an example there you 
might be able to use.

--
* Greg Smith gsmith(at)gregsmith(dot)com http://www.gregsmith.com Baltimore, MD

In response to

pgsql-performance by date

Next:From: Greg SmithDate: 2008-10-13 21:37:53
Subject: Re: "Mysterious" issues with newly installed 8.3
Previous:From: Carlos MorenoDate: 2008-10-13 19:56:58
Subject: Re: "Mysterious" issues with newly installed 8.3

pgsql-general by date

Next:From: Craig BennettDate: 2008-10-14 00:02:04
Subject: Re: Chart of Accounts
Previous:From: ArtacusDate: 2008-10-13 20:09:53
Subject: Re: PL/pgSQL stored procedure returning multiple result sets (SELECTs)?

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group