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Date: Mon, 7 Mar 2011 08:22:16 -0600
From: Kenneth Marshall <ktm@rice.edu>
To: Andreas For? Tollefsen <andreasft@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Performance issues
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On Mon, Mar 07, 2011 at 03:17:05PM +0100, Andreas For? Tollefsen wrote:
> Thanks, Ken.
> 
> It seems like the tip to turn off synchronous_commit did the trick:
> 
> /usr/lib/postgresql/8.4/bin/pgbench -T 60 test1
> starting vacuum...end.
> transaction type: TPC-B (sort of)
> scaling factor: 1
> query mode: simple
> number of clients: 1
> duration: 60 s
> number of transactions actually processed: 86048
> tps = 1434.123199 (including connections establishing)
> tps = 1434.183362 (excluding connections establishing)
> 
> Is this acceptable compared to others when considering my setup?
> 
> Cheers,
> Andreas
> 


These are typical results for synchronous_commit off. The caveat
is you must be able to handle loosing transactions if you have a
database crash, but your database is still intact. This differs
from turning fsync off in which a crash means you would need to
restore from a backup.

Cheers,
Ken