pg.ddx.io  pgsql-performance@postgresql.org mailing list archive  

help / color / mirror / Atom feed
From: Mark Kirkwood <markir@paradise.net.nz>
To: Scott Marlowe <scott.marlowe@gmail.com>
Cc: Adonias Malosso <malosso@gmail.com>
Cc: Claus Guttesen <kometen@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: 4s query want to run faster
Date: Fri, 22 Feb 2008 18:10:18 +1300
Message-ID: <47BE593A.8000709@paradise.net.nz> (raw)
In-Reply-To: <dcc563d10802211516x65e80eb4o3d9975e626b3a760@mail.gmail.com>
References: <8a5d3c890802211248k7d9dfbb5ndd645358a84130a7@mail.gmail.com>
	<b41c75520802211310j40c51014y5d6fbc56bf38c467@mail.gmail.com>
	<8a5d3c890802211311m5fab66d6q865fda1737e47802@mail.gmail.com>
	<b41c75520802211316q35954881q26a6a6058efefcbf@mail.gmail.com>
	<8a5d3c890802211323j2a7e2ebdye42f988222046e44@mail.gmail.com>
	<47BE023A.6000905@paradise.net.nz>
	<dcc563d10802211516x65e80eb4o3d9975e626b3a760@mail.gmail.com>

Scott Marlowe wrote:
>
> effective_cache_size is pretty easy to set, and it's not real
> sensitive to small changes, so guesstimation is fine where it's
> concerned.  Basically, let your machine run for a while, then  add the
> cache and buffer your unix kernel has altogether (top and free will
> tell you these things).  If you're running other apps on the server,
> make a SWAG (scientific wild assed guess) how much the other apps are
> pounding on the kernel cache / buffer and set effective_cache_size to
> how much you think postgresql is using of the total and set it to
> that.
>   

FWIW - The buffered|cached may well be called something different if you 
are not on Linux (I didn't see any platform mentioned - sorry if I 
missed it) - e.g for Freebsd it is "Inactive" that shows what the os is 
caching and "Cached" actually means something slightly different... (yep 
that's caused a lot of confusion in the past...)

Cheers

Mark



view thread (12+ messages)

Message-ID: <47BE593A.8000709@paradise.net.nz>
Permalink:  ../47BE593A.8000709@paradise.net.nz/
Also on:    postgresql.org/message-id/47BE593A.8000709@paradise.net.nz

 · 

reply
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: markir@paradise.net.nz, scott.marlowe@gmail.com, malosso@gmail.com, kometen@gmail.com
  Subject: Re: 4s query want to run faster
  In-Reply-To: <47BE593A.8000709@paradise.net.nz>

* 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