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

Re: [ADMIN] shared_buffers and shmmax

From: Bruce Momjian <bruce(at)momjian(dot)us>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: valiouk(at)yahoo(dot)co(dot)uk, pgsql-docs(at)postgresql(dot)org, dx k9 <bitsandbytes88(at)hotmail(dot)com>
Subject: Re: [ADMIN] shared_buffers and shmmax
Date: 2008-12-15 23:23:02
Message-ID: 200812152323.mBFNN3Y25121@momjian.us (view raw or flat)
Thread:
Lists: pgsql-adminpgsql-docspgsql-hackers
Tom Lane wrote:
> [ redirecting to pgsql-docs ]
> 
> Valentin Bogdanov <valiouk(at)yahoo(dot)co(dot)uk> writes:
> >> From: dx k9 <bitsandbytes88(at)hotmail(dot)com>
> >> I'm trying to understand what the documentation means
> >> by bytes per increment, what is the increment supposed to
> >> be bytes, MB, or Kb.
> 
> > shared_buffers is in disk block size, typically 8K, at least that's what it is on Linux platforms. shmmax is quite simply in bytes.
> 
> The table the OP is looking at (table 17.2 in the 8.3 docs) predates
> the ability to specify shared_buffers in KB or MB instead of
> number-of-buffers.  I agree it's not entirely obvious that what it
> means is "multiply your setting in KB/MB by 8400/8192".  Anybody have
> an idea how to clarify things?

I have updated the table title to be clearer.

-- 
  Bruce Momjian  <bruce(at)momjian(dot)us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +

Attachment: /rtmp/diff
Description: text/x-diff (1023 bytes)

In response to

Responses

pgsql-docs by date

Next:From: Bruce MomjianDate: 2008-12-15 23:32:36
Subject: Re: [ADMIN] shared_buffers and shmmax
Previous:From: Fujii MasaoDate: 2008-12-06 04:29:10
Subject: Re: BUG #4566: pg_stop_backup() reports incorrect STOP WAL LOCATION

pgsql-hackers by date

Next:From: Bruce MomjianDate: 2008-12-15 23:32:36
Subject: Re: [ADMIN] shared_buffers and shmmax
Previous:From: Simon RiggsDate: 2008-12-15 22:30:56
Subject: Re: [PATCHES] odd output in restore mode

pgsql-admin by date

Next:From: Bruce MomjianDate: 2008-12-15 23:32:36
Subject: Re: [ADMIN] shared_buffers and shmmax
Previous:From: Jaime CasanovaDate: 2008-12-15 21:31:39
Subject: Re: Urgente error in restore prod

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