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[PATCH] ALTER TABLE SET (compress_max_size... = )

From: "Alex Hunsaker" <badalex(at)gmail(dot)com>
To: PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: [PATCH] ALTER TABLE SET (compress_max_size... = )
Date: 2009-01-04 23:32:44
Message-ID: 34d269d40901041532q1a8b8b12l4461d534c671deef@mail.gmail.com (view raw or flat)
Thread:
Lists: pgsql-hackers
This patch lets you control 3 pg_lzcompress knobs on a per table basis
(note requires reloptions.patch)

compress_max_size:  Controls the maximum size to be considered for
TOAST compression.
compress_min_rate: Minimum compression rate (0-100%) required for
TOAST compression to be used.
compress_success_by: if by this byte no compressible data found abort
compression.

Note this adds some documentation, but I was having a hard time coming
up with a good way to describe these.  I'm also not very happy with
the names.  I originally tried something like toast.max_input_size.
But decided later if we allow you to set toast attributes that might
be confusing.  So help with verbiage and names is appreciated.

Also I only did those 3 because they seemed the 3 most useful things
someone would want to tune.  Later if we need to we can export them
all and make them per column settings (and maybe you can pick a
compression algo or what not...)  But I figured lets start small.

I thought about doing another cleanup patch to get rid of
PGLZ_Strategy_default and PGLZ_Strategy_always.  Nothing uses the
later, and if we expose all the nobs nothing will use the first.
Comments?

Attachment: compress_opts.patch
Description: application/octet-stream (9.4 KB)

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Next:From: Tom LaneDate: 2009-01-04 23:37:08
Subject: Re: generic reloptions improvement
Previous:From: Alex HunsakerDate: 2009-01-04 23:10:49
Subject: Re: generic reloptions improvement

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