Message-ID: <47A87618.1090203@archonet.com>
Date: Tue, 05 Feb 2008 14:43:36 +0000
From: Richard Huxton <dev@archonet.com>
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To: Simon Riggs <simon@2ndquadrant.com>
CC: Dimitri Fontaine <dfontaine@hi-media.com>,
	pgsql-performance@postgresql.org, "Jignesh K. Shah" <J.K.Shah@sun.com>,
	Greg Smith <gsmith@gregsmith.com>
Subject: Re: Benchmark Data requested
References: <1202150236.4252.521.camel@ebony.site>	
	<Pine.GSO.4.64.0802041500460.799@westnet.com>
	<47A797E5.4000507@sun.com>	
	<200802051506.51581.dfontaine@hi-media.com>
	<1202221496.4252.680.camel@ebony.site>
In-Reply-To: <1202221496.4252.680.camel@ebony.site>
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Simon Riggs wrote:
> On Tue, 2008-02-05 at 15:06 +0100, Dimitri Fontaine wrote:
>>
>> Le lundi 04 f=C3=A9vrier 2008, Jignesh K. Shah a =C3=A9crit :

>>> Multiple table loads ( 1 per table) spawned via script  is bit better
>>> but hits wal problems.
>> pgloader will too hit the WAL problem, but it still may have its benef=
its, or=20
>> at least we will soon (you can already if you take it from CVS) be abl=
e to=20
>> measure if the parallel loading at the client side is a good idea perf=
. wise.
>=20
> Should be able to reduce lock contention, but not overall WAL volume.

In the case of a bulk upload to an empty table (or partition?) could you=20
not optimise the WAL away? That is, shouldn't the WAL basically be a=20
simple transformation of the on-disk blocks? You'd have to explicitly=20
sync the file(s) for the table/indexes of course, and you'd need some=20
work-around for WAL shipping, but it might be worth it for you chaps=20
with large imports.

--=20
   Richard Huxton
   Archonet Ltd