From: Olleg <olleg_s@mail.ru>
To: Ron <rjpeace@earthlink.net>
Cc: pgsql-performance@postgresql.org
Subject: Re: BLCKSZ
Date: Tue, 06 Dec 2005 13:40:47 +0300
Message-ID: <43956AAF.7060108@mail.ru> (raw)
In-Reply-To: <6.2.5.6.0.20051205183120.01dd6a80@earthlink.net>
References: <dn1gdd$19kg$1@news.hub.org>
<29518.1133794958@sss.pgh.pa.us>
<4394B1D3.7000304@mail.ru>
<6.2.5.6.0.20051205183120.01dd6a80@earthlink.net>
Ron wrote:
> In general, and in a very fuzzy sense, "bigger is better". pg files are
> laid down in 1GB chunks, so there's probably one limitation.
Hm, expect result of tests on other platforms, but if there theoretical
dispute...
I can't undestand why "bigger is better". For instance in search by
index. Index point to page and I need load page to get one row. Thus I
load 8kb from disk for every raw. And keep it then in cache. You
recommend 64kb. With your recomendation I'll get 8 times more IO
throughput, 8 time more head seek on disk, 8 time more memory cache (OS
cache and postgresql) become busy. I have small row in often loaded
table, 32 bytes. Table is not clustered, used several indices. And you
recommend load 64Kb when I need only 32b, isn't it?
--
Olleg
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To: pgsql-performance@postgresql.org
Cc: olleg_s@mail.ru, rjpeace@earthlink.net
Subject: Re: BLCKSZ
In-Reply-To: <43956AAF.7060108@mail.ru>
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