Re: [PATCHES] Full page writes improvement, code update

From: "Simon Riggs" <simon(at)2ndquadrant(dot)com>
To: "Richard Huxton" <dev(at)archonet(dot)com>
Cc: "Zeugswetter Andreas ADI SD" <ZeugswetterA(at)spardat(dot)at>, "Koichi Suzuki" <suzuki(dot)koichi(at)oss(dot)ntt(dot)co(dot)jp>, <josh(at)agliodbs(dot)com>, <pgsql-hackers(at)postgresql(dot)org>, <pgsql-patches(at)postgresql(dot)org>
Subject: Re: [PATCHES] Full page writes improvement, code update
Date: 2007-03-30 11:21:29
Message-ID: 1175253689.4386.749.camel@silverbirch.site
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers pgsql-patches

On Fri, 2007-03-30 at 11:27 +0100, Richard Huxton wrote:

> Is that always true? Could the backup not pick up a partially-written
> page? Assuming it's being written to as the backup is in progress. (We
> are talking about when disk blocks are smaller than PG blocks here, so
> can't guarantee an atomic write for a PG block?)

Any page written during a backup has a backup block that would not be
removable by Koichi's tool, so yes, you'd still be safe.

i.e. between pg_start_backup() and pg_stop_backup() we always use full
page writes, even if you are running in full_page_writes=off mode.

--
Simon Riggs
EnterpriseDB http://www.enterprisedb.com

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message NikhilS 2007-03-30 11:26:30 Re: UPDATE using sub selects
Previous Message Marko Kreen 2007-03-30 11:06:36 Re: Proposal: include PL/Proxy into core

Browse pgsql-patches by date

  From Date Subject
Next Message Heikki Linnakangas 2007-03-30 11:28:32 Re: Make CLUSTER MVCC-safe
Previous Message Zeugswetter Andreas ADI SD 2007-03-30 10:33:04 Re: [PATCHES] Full page writes improvement, code update