From: Chander Ganesan <chander@otg-nc.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Jonny <blubb@terminalschmiede.de>
Cc: pgsql-admin@postgresql.org
Subject: Re: turning of pg_xlog
Date: Tue, 30 Sep 2008 14:55:19 -0400
Message-ID: <48E27617.7020005@otg-nc.com> (raw)
In-Reply-To: <23386.1222800278@sss.pgh.pa.us>
References: <48E0B559.3070406@terminalschmiede.de>
<48E26C60.3060307@otg-nc.com>
<23386.1222800278@sss.pgh.pa.us>
Tom Lane wrote:
> Chander Ganesan <chander@otg-nc.com> writes:
>
>> You should also understand that if you set checkpoint_segments to a
>> small number, its still possible that PostgreSQL might use more than
>> that number for a large transaction.
>>
>
> "Large transactions" have nothing to do with this. You are confusing
> Postgres' implementation with Oracle's.
>
> regards, tom lane
Okay. I guess my use of the word "transaction" here was erroneous -
probably comes from my oracle background :-( . However, the fact
remains that its possible to exceed checkpoint_segments in certain
scenarios (I think the docs refer to it as a peak in log creation or
something like that), which - if it fills up the disk that the WALs are
on, can result in issues... And one should be wary of that when trying
to limit the number of WALs in order to meet limited disk space
requirements.
--
Chander Ganesan
Open Technology Group, Inc.
One Copley Parkway, Suite 210
Morrisville, NC 27560
919-463-0999/877-258-8987
http://www.otg-nc.com
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-admin@postgresql.org
Cc: chander@otg-nc.com, tgl@sss.pgh.pa.us, blubb@terminalschmiede.de
Subject: Re: turning of pg_xlog
In-Reply-To: <48E27617.7020005@otg-nc.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