| From: | Bruce Momjian <bruce(at)momjian(dot)us> |
|---|---|
| To: | Rahila Syed <rahilasyed90(at)gmail(dot)com> |
| Cc: | "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: [REVIEW] Re: Compression of full-page-writes |
| Date: | 2014-12-11 16:34:59 |
| Message-ID: | 20141211163459.GB19832@momjian.us |
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| Thread: | |
| Lists: | pgsql-hackers |
On Thu, Dec 11, 2014 at 01:26:38PM +0530, Rahila Syed wrote:
> >I am sorry but I can't understand the above results due to wrapping.
> >Are you saying compression was twice as slow?
>
> CPU usage at user level (in seconds) for compression set 'on' is 562 secs
> while that for compression set 'off' is 354 secs. As per the readings, it
> takes little less than double CPU time to compress.
> However , the total time taken to run 250000 transactions for each of the
> scenario is as follows,
>
> compression = 'on' : 1838 secs
> = 'off' : 1701 secs
>
>
> Different is around 140 secs.
OK, so the compression took 2x the cpu and was 8% slower. The only
benefit is WAL files are 35% smaller?
--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ Everyone has their own god. +
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