Yes, we are in a data warehouse like environments, where the database server is used to hold very large volumn of read only historical data, CPU, memory, I/O and network are all OK now except storage space, the only goal of compression is to reduce storage consumption.
> Date: Thu, 30 Oct 2008 10:53:27 +1100
> From: gxallen@gmail.com
> To: pgsql-general@postgresql.org
> Subject: Re: [GENERAL] Are there plans to add data compression feature to postgresql?
>
> Tom Lane wrote:
> > 小波 顾 <guxiaobo1982@hotmail.com> writes:
> >
> >> [ snip a lot of marketing for SQL Server ]
> >>
> >
> > I think the part of this you need to pay attention to is
> >
> >
> >> Of course, nothing is entirely free, and this reduction in space and
> >> time come at the expense of using CPU cycles.
> >>
> >
> > We already have the portions of this behavior that seem to me to be
> > likely to be worthwhile (such as NULL elimination and compression of
> > large field values). Shaving a couple bytes from a bigint doesn't
> > strike me as in teresting.
>
> Think about it on a fact table for a warehouse. A few bytes per bigint
> multiplied by several billions/trillions of bigints (not an exaggeration
> in a DW) and you're talking some significant storage saving on the main
> storage hog in a DW. Not to mention the performance _improvements_ you
> can get, even with some CPU overhead for dynamic decompression, if the
> planner/optimiser understands how to work with the compression index/map
> to perform things like range/partition elimination etc. Admittedly this
> depends heavily on the storage mechanics and optimisation techniques of
> the DB, but there is value to be had there ... IBM is seeing typical
> storage savings in the 40-60% range, mostly based on boring,
> bog-standard int, char and varchar data.
>
> The IDUG (so DB2 users themselves, not IBM's marketing) had a
> competition to see what was happening in the real world, take a look if
> interested: http://www.idug.org/wps/portal/idug/compressionchallenge
>
> Other big benefits come with XML ... but that is even more dependent on
> the starting point. Oracle and SQL Server will see big benefits in
> compression with this, because their XML technology is so
> mind-bogglingly broken in the first place.
>
> So there's certainly utility in this kind of feature ... but whether it
> rates above some of the other great stuff in the PostgreSQL pipeline is
> questionable.
>
> Ciao
> Fuzzy
> :-)
>
> ------------------------------------------------
> Dazed and confused about technology for 20 years
> http://fuzzydata.wordpress.com/
>
>
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