Re: PITR: XLog File compression on Archive - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: PITR: XLog File compression on Archive
Date
Msg-id 200408232157.i7NLvar13521@candle.pha.pa.us
Whole thread Raw
In response to Re: PITR: XLog File compression on Archive  (Alvaro Herrera <alvherre@dcc.uchile.cl>)
List pgsql-hackers
Alvaro Herrera wrote:
> On Mon, Aug 23, 2004 at 10:03:26PM +0100, Simon Riggs wrote:
> 
> Simon,
> 
> > I raise this now because I'm thinking that this functionality really ought
> > to be in the main production 8.0 release. Not sure if anybody will
> > agree....but that's what I'm thinking now, based upon what seems like a
> > simple design to put it there. My rationale is that it will be simpler to
> > support one file format than two, if we introduce the change at a later
> > time.
> 
> Why do you talk about another file format?  AFAIU it's the same format,
> only the archived files will lack the page images.  Maybe I'm missing
> something?
> 
> Anyway I think we are way past feature freeze, and XLog "compression"
> could made it into 8.1 without loss of functionality.  At that point we
> will say "now PITR uses less space on the archiver" and that's it.
> 
> (Maybe we could even think about LZ-compressing the remaining WAL
> entries on the archived logs?)

Agreed.  I added a mention of it in the TODO list:

* Eliminate need to write full pages to WAL before page modification
 Currently, to protect against partial disk page writes, we write the full page images to WAL before they are modified
sowe can correct any partial page writes during recovery.  These pages can also be eliminated from point-in-time
archivefiles.
 



--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
359-1001+  If your life is a hard drive,     |  13 Roberts Road +  Christ can be your backup.        |  Newtown Square,
Pennsylvania19073
 


pgsql-hackers by date:

Previous
From: Alvaro Herrera
Date:
Subject: Re: PITR: XLog File compression on Archive
Next
From: Gaetano Mendola
Date:
Subject: Re: PITR: XLog File compression on Archive