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

Alex Hunsaker wrote:
> 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?

I think we need to live with the TOAST changes for at least one release
before we know what knobs we will need.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
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