Raw vs. Cooked

I am the dba for our shop's Informix based app. We use raw devices on our Sun Solaris boxes.

We are about ready to start the process of redeveloping our agency's main app using Oracle. I am starting to familiarize myself with Oracle.

I'm wondering about the ole cooked vs. raw space issue.

In my Informix experience, I am quite comfortable using raw space. However,I have gotten the impression
from Oracle folks (for example, an Oracle instructor) that the customary practice with Oracle is to use cooked space. In fact, the instructor said there wouldn't be any difference, so he suggested using "the more
convenient" cooked space. To me, it doesn't really seem inconvenient to
use raw, so I would be happy to go that way if there is a performance gain (which seems likely to me). I am assuming that there exist Oracle utilities to
handle backups or loading/unloading raw storage.

Anyway, while considering this, I found a recent (April 2004) Oracle white paper that
seems to support my personal bias (don't we just love to see our prejudices reinforced?). It is called "A Quantitative Comparison Between Raw Devices and File Systems for Implementing Oracle Databases". It can be found here:

http://www.oracle.com/technology/deploy/performance/pdf/TWP_Oracle_HP_files.pdf

It concludes that using raw devices is much superior to cooked. But, perhaps that conclusion is meant to apply specifically to HP platforms, since that was the basis of the paper.

Anyway, among the Oracle cogniscenti, is raw really generally avoided in favor of cooked? Does this paper challenge the generally accepted Oracle practice? Is there a generally accepted "factoid" in the Oracle world that either raw or cooked is "the way to go"?

We will be using one big S.A.M.E. RAID10 device. The question is to cook or not to cook, and administrative difficulties of raw vs cooked are not an issue (assuming suitable Oracle tools exist). Thank you for any comments. Received on Thu Dec 16 2004 - 14:48:39 CST