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Re: [PATCHES] Full page writes improvement, code update

Josh Berkus <josh@agliodbs.com>

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From: Josh Berkus <josh@agliodbs.com>
To: pgsql-hackers@postgresql.org
Cc: "Simon Riggs" <simon@2ndquadrant.com>, "Koichi Suzuki" <suzuki.koichi@oss.ntt.co.jp>, pgsql-patches@postgresql.org
Date: 2007-03-29T18:45:27Z
Lists: pgsql-hackers 
Simon,

> OK, different question:
> Why would anyone ever set full_page_compress = off?

The only reason I can see is if compression costs us CPU but gains RAM & 
I/O.  I can think of a lot of applications ... benchmarks included ... 
which are CPU-bound but not RAM or I/O bound.  For those applications, 
compression is a bad tradeoff.

If, however, CPU used for compression is made up elsewhere through smaller 
file processing, then I'd agree that we don't need a switch.

-- 
--Josh

Josh Berkus
PostgreSQL @ Sun
San Francisco