Re: Restore of pg_dump taking a long time...

From: Jim Nasby <jnasby(at)pervasive(dot)com>
To: Todd A(dot) Cook <tcook(at)blackducksoftware(dot)com>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Ruairi <rcarroll(at)bluemetrix(dot)com>, pgsql-admin(at)postgresql(dot)org
Subject: Re: Restore of pg_dump taking a long time...
Date: 2006-05-25 20:51:54
Message-ID: 6D7A0D55-3364-4733-B721-90BDC0D252C6@pervasive.com
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On May 24, 2006, at 2:56 PM, Todd A. Cook wrote:

> Tom Lane wrote:
>> "Todd A. Cook" <tcook(at)blackducksoftware(dot)com> writes:
>>> I have found that increasing maintenance_work_mem can decrease index
>>> build speed on large tables:
>> You should probably re-measure when 8.2 comes out; we've fixed a
>> number
>> of performance issues in the sorting code that might cause that.
>
> Thanks. I'll do that. If I can, I'll try it sooner on a build
> from CVS.

If you'll be messing around with CVS, you might also want to try this
patch: http://jim.nasby.net/misc/pgsqlcompression/compress-sort.patch
(which was written by someone else). It hacks compression into the on-
disk sort code, which has shown a 50% speed improvement on my
machine. It should be fine to use for loading a database, but you
wouldn't want to leave it in for serious use (IIRC there's some cases
it flat-out doesn't handle right now).

You could probably apply that to 8.1.4 as well if you wanted to; it
should be fine for just loading the database.
--
Jim C. Nasby, Sr. Engineering Consultant jnasby(at)pervasive(dot)com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461

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