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(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ If your life is a hard drive, Christ can be your backup. +