From: Dave Crooke <dcrooke@gmail.com>
To: David Newall <postgresql@davidnewall.com>
Cc: pgsql-performance@postgresql.org, robertmhaas@gmail.com, Tom Lane <tgl@sss.pgh.pa.us>
Cc: Craig Ringer <craig@postnewspapers.com.au>
Subject: GZIP of pre-zipped output
Date: Sun, 21 Mar 2010 12:04:00 -0500
Message-ID: <ca24673e1003211004l68237f72r101eb04082f8e288@mail.gmail.com> (raw)
If you are really so desparate to save a couple of GB that you are resorting
to -Z9 then I'd suggest using bzip2 instead.
bzip is designed for things like installer images where there will be
massive amounts of downloads, so it uses a ton of cpu during compression,
but usually less than -Z9 and makes a better result.
Cheers
Dave
On Mar 21, 2010 10:50 AM, "David Newall" <postgresql@davidnewall.com> wrote:
Tom Lane wrote:
>
> I would bet that the reason for the slow throughput is that gzip
> is fruitlessl...
Indeed, I didn't expect much reduction in size, but I also didn't expect a
four-order of magnitude increase in run-time (i.e. output at 10MB/second
going down to 500KB/second), particularly as my estimate was based on
gzipping a previously gzipped file. I think it's probably pathological
data, as it were. Might even be of interest to gzip's maintainers.
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To: pgsql-performance@postgresql.org
Cc: dcrooke@gmail.com, postgresql@davidnewall.com, tgl@sss.pgh.pa.us, craig@postnewspapers.com.au
Subject: Re: GZIP of pre-zipped output
In-Reply-To: <ca24673e1003211004l68237f72r101eb04082f8e288@mail.gmail.com>
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