Re: How do I use raw devices?

In article <1994Mar21.075412.1_at_corp02.d51.lilly.com>, jl34778_at_corp02.d51.lilly.com writes:
|> I am running ORACLE 7.0.15.4 on a SparcServer 1000, running Solaris 2.3. I am
|> beginning to look into using raw devices, and wondered if anyone has any advice
|> for me.
|>
|> The two reasons why I'd like to use them are:
|>
|> a. To decrease the annoying 20% space overhead that seems to come with
|> formating a drive and putting a file system on it.
|> b. To increase I/O performance.

There is a paper titled, Making the Decision to Use UNIX Raw Devices, by Cary Millsap, cmillsap_at_us.oracle.com, which basically recommends not to use raw devices except in very high transaction loads. The author claims that many people experience improved performance going from a UNIX file system to raw devices simply because when the data is reloaded, row chaining is reduced and the indexes are rebalanced. The same effect can be experienced going from raw devices to a UNIX filesystem!

--
Alan Beal
Loral Federal Systems
Owego, NY
(607) 751-2026       alanb_at_vnet.ibm.com