Skip site navigation (1) Skip section navigation (2)

Re: Improve compression speeds in pg_lzcompress.c

From: Robert Haas <robertmhaas(at)gmail(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Takeshi Yamamuro <yamamuro(dot)takeshi(at)lab(dot)ntt(dot)co(dot)jp>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Improve compression speeds in pg_lzcompress.c
Date: 2013-01-07 21:07:51
Message-ID: (view raw or whole thread)
Lists: pgsql-hackers
On Mon, Jan 7, 2013 at 11:16 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Why would that be a good tradeoff to make?  Larger stored values require
> more I/O, which is likely to swamp any CPU savings in the compression
> step.  Not to mention that a value once written may be read many times,
> so the extra I/O cost could be multiplied many times over later on.

I agree with this analysis, but I note that the test results show it
actually improving things along both parameters.

I'm not sure how general that result is.

Robert Haas
The Enterprise PostgreSQL Company

In response to


pgsql-hackers by date

Next:From: Kohei KaiGaiDate: 2013-01-07 21:14:32
Subject: Re: ALTER command reworks
Previous:From: Tom LaneDate: 2013-01-07 21:06:23
Subject: Re: ALTER command reworks

Privacy Policy | About PostgreSQL
Copyright © 1996-2015 The PostgreSQL Global Development Group