Re: Significantly larger toast tables on 8.4?

Alex Hunsaker <badalex@gmail.com>

From: "Alex Hunsaker" <badalex@gmail.com>
To: "Robert Haas" <robertmhaas@gmail.com>
Cc: "Tom Lane" <tgl@sss.pgh.pa.us>, "Stephen R. van den Berg" <srb@cuci.nl>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2009-01-02T19:42:56Z
Lists: pgsql-hackers
On Fri, Jan 2, 2009 at 10:44, Robert Haas <robertmhaas@gmail.com> wrote:
> Here, we have a case where the space savings are potentially much
> larger, and the only argument against it is that someone might be
> disappointed in the performance of substring operations, if they
> happen to do any.  What if they know that they don't want to do any
> and want to get compression?  Even if the benefit is only 1.5X on
> their data rather than 10X, that seems like a pretty sane and useful
> thing to want to do.  It's easy to shut off compression if you don't
> want it; if the system makes an arbitrary decision to disable it, how
> do you get it back?

I think we could just add another toast storage type: alter table
alter column set storage compress; ?  It seems overkill to expose
PGLZ_Strategy knobs per column...