Re: Compressing table images

Joshua D. Drake wrote:
> Brian Hurt wrote:
> >My apologies if this subject has already been hashed to death, or if
> >this is the wrong list, but I was wondering if people had seen this paper:
> >http://www.cwi.nl/htbin/ins1/publications?request=intabstract&key=ZuHeNeBo:ICDE:06
> >
> >
> >Basically it describes a compression algorithm for tables of a
> >database. The huge advantage of doing this is that it reduced the disk
> >traffic by (approximately) a factor of four- at the cost of more CPU
> >utilization.
> >Any thoughts or comments?
>
> I don't know if that is the algorithm we use but PostgreSQL will
> compress its data within the table.

But only in certain very specific cases. And we compress on a
per-attribute basis. Compressing at the page level is pretty much out
of the question; but compressing at the tuple level I think is doable.
How much benefit that brings is another matter. I think we still have
more use for our limited manpower elsewhere.

--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support