Re: BLCKSZ - Mailing list pgsql-performance

From Olleg
Subject Re: BLCKSZ
Date
Msg-id 43956AAF.7060108@mail.ru
Whole thread Raw
In response to Re: BLCKSZ  (Ron <rjpeace@earthlink.net>)
Responses Re: BLCKSZ
List pgsql-performance
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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