Re: Tablespaces

On Thu, 26 Feb 2004, Dennis Bjorklund wrote:

> On Thu, 26 Feb 2004, Gavin Sherry wrote:
>
> > Comments? Questions? Suggestions?
>
> Is that plan that in the future one can split a single table into
> different table spaces? Like storing all rows with year < 1999 in one
> tablespace and the rest in another?

These are called partitions in oracle. You can approximate this with table
spaces by using a partial index and putting it in a different table space.
The problem, of course, is seq scans.

>
> With the rule system and two underlying tables one could make it work by
> hand I think.
>
> I've never used tablespaces in oracle so I don't know what it can offer. I

Certainly, table spaces are used in many ways in oracle, db2, etc. You can
mirror data across them, have different buffer sizes for example.
In some implementations, they can be raw disk partitions (no file system).
I don't intend going this far, however.

> If you don't want to discuss this now, I understand. It's not part of the
> design as it is now. I'm just curious at what direction we are moving and
> what is possible to do.

Well, partitions are something else entirely. Mirroring would be
interesting, but RAID designers are better at parallelisation of IO than
(some) database developers. Might be better to keep the problem seperate.

Gavin