public inbox for [email protected]  

help / color / mirror / Atom feed

From: Bruce Momjian <[email protected]>
To: Alvaro Herrera <[email protected]>
Cc: Tom Lane <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: dx k9 <[email protected]>
Subject: Re: [ADMIN] shared_buffers and shmmax
Date: Mon, 15 Dec 2008 18:46:00 -0500 (EST)
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

Alvaro Herrera wrote:
> Bruce Momjian wrote:
> > Tom Lane wrote:
> > > [ redirecting to pgsql-docs ]
> > > 
> > > Valentin Bogdanov <[email protected]> writes:
> > > >> From: dx k9 <[email protected]>
> > > >> 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.
> 
> I don't find it any clearer ... I think the missing clue is that if you
> specify shared_buffers values in MB, you must divide the value by block
> size.

Well, the heading says "object" now so I thought it would suggest we are
talking about objects and not bytes.

> > ***************
> > *** 1119,1125 ****
> >   
> >         <row>
> >          <entry>Fixed space requirements</>
> > !        <entry>770 kB</entry>
> >         </row>
> >        </tbody>
> >       </tgroup>
> > --- 1119,1125 ----
> >   
> >         <row>
> >          <entry>Fixed space requirements</>
> > !        <entry>770 k</entry>
> >         </row>
> >        </tbody>
> >       </tgroup>
> 
> This change is wrong, why did you do it?

The heading says "bytes" so having the "B" was unnecessary and possibly
confusing.


-- 
  Bruce Momjian  <[email protected]>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

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

view thread (28+ messages)  latest in thread

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: [email protected]
  Cc: [email protected], [email protected], [email protected], [email protected], [email protected]
  Subject: Re: [ADMIN] shared_buffers and shmmax
  In-Reply-To: <[email protected]>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox