Message-ID: <50063997.9030509@ringerc.id.au>
Date: Wed, 18 Jul 2012 12:20:39 +0800
From: Craig Ringer <ringerc@ringerc.id.au>
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To: Greg Smith <greg@2ndQuadrant.com>
CC: Tom Lane <tgl@sss.pgh.pa.us>, Robert Haas <robertmhaas@gmail.com>,
	Jeff Janes <jeff.janes@gmail.com>,
	pgsql-hackers <pgsql-hackers@postgresql.org>,
	Daniel Farina <daniel@heroku.com>,
	=?ISO-8859-1?Q?=22Harold_A=2E_Gim=E9nez=22?= <harold.gimenez@gmail.com>
Subject: Re: Checkpointer split has broken things dramatically (was
	Re: DELETE vs TRUNCATE explanation)
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On 07/18/2012 12:00 PM, Greg Smith wrote:

> The second justification for the split was that it seems easier to get 
> a low power result from, which I believe was the angle Peter Geoghegan 
> was working when this popped up originally.  The checkpointer has to 
> run sometimes, but only at a 50% duty cycle as it's tuned out of the 
> box.  It seems nice to be able to approach that in a way that's power 
> efficient without coupling it to whatever heartbeat the BGW is running 
> at.  I could even see people changing the frequencies for each 
> independently depending on expected system load.  Tune for lower power 
> when you don't expect many users, that sort of thing.
>
Yeah - I'm already seeing benefits from that on my laptop, with much 
less need to stop Pg when I'm not using it.

--
Craig Ringer