Re: Would like to know more about tablespaces

In article <33282F4B.3839_at_chsra.wisc.edu>

           dora_at_chsra.wisc.edu "Dora Kilburn" writes:

> I have some questions about Oracle tablespaces. We would like to
> separate our tables into tablespaces in some sensible way, but we may be
> limited to a single disk controller.
>
> Can performance be improved at all by spreading tables, indexes, etc.
> across multiple tablespaces on a single drive, or do you have to have
> files spread across multiple drives? We can, of course, plan for any
> possible future hardware upgrades.
>
> Are there any downsides or pitfalls in creating too many tablespaces?
> How do you know if you have too many tablespaces or too many datafiles?
>
> Also, we are curious about whether it is possible to use a RAM drive or
> virtual drive for datafiles. I suspect that it is not possible to use
> it for any kind of permanent table or permanent tablespace.
>
> I am new to Oracle and these points were not covered to my satisfaction
> in either the Oracle7 Server manual or Oracle Performance Tuning (Mark
> Gurry & Peter Corrigan). I would appreciate any wisdom that you
> experienced and knowledgeable people may have.
>

RAM drives are (AFAIK) not possible and are probably undesirable bearing in mind the amount of caching carried out by Oracle itself.

The single controller is not a problem unless you are hitting the throughput limit (independent of the number of tablespaces of course).

The best book I have come across about this is 'The Oracle DBA HAndbook' by Kevin Loney. Published by Oracle Press (Osborne). It has a whole chapter discussing possible tablespace layouts.

-- 
Keith Matthews