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Date: Mon, 22 Sep 2014 14:04:20 -0400
From: Peter Eisentraut <peter_e@gmx.net>
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To: "Huang, Suya" <Suya.Huang@au.experian.com>,
 "pgsql-admin@postgresql.org" <pgsql-admin@postgresql.org>
Subject: Re: How to interpret view pg_stat_bgwriter
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On 9/19/14 1:54 AM, Huang, Suya wrote:
> How to compare buffers_backend against buffers_checkpoint?

This is a very general question, but generally you want buffers_backend
to be as small as possible.

> Below is some statistics of check point activities happened on the day while backend is loading data:
> 
> Day 	Hour 	Written buffers 	Write time 	Sync time 	Total time
> 	06	107,338	  		1,475.583s	3.142s		1,478.828s
> 	07	601,672	  		1,041.482s	348.215s	1,390.153s
> 	08	3,613			361.422s	0.053s		361.535s
> 	09	1,006,704		1,456.898s	14.501s		1,471.545s
> 	10	1,116,463		1,987.896s	6.164s		1,995.11s
> 
> Can we tell something about the configuration?

If this is while loading data, there isn't much to say.  I'd be worried
about the 348s sync time if this were during normal transaction
processing load.


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