Would like to know more about tablespaces

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.

Thanks,

Dora

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