Re: Raw Devices

In article <7oqi1o$pni$1_at_autumn.news.rcn.net>,   "Tom Baker" <tcbaker_at_erols.com> wrote:
> Hi:
>
> I am an ex Sybase DBA and new to Oracle. In Sybase you use raw
devices for
> performance and safety of your data from server failures.
>
> I have read that Oracle is betten on cooked files. Is this true? Any
> suggestions?
>
> Thanks in advance.
>
> Tom
> tcbaker_at_erols.com
>

Oracle does not run better on cooked, normal OS, files; but most Unix administrators and DBA's probably find ufx file systems easier to understand and work with. We use Unix files for all our test systems and both Unix files and raw partitions for production. The more important the database the more likely we are using raw partitions for the small but still important performance improvement.

Depending on your platform you may be able to use direct i/o to bypass the Unix buffer pool instead of raw partitions and get much of the same performance. Note that if you use raw partitions you want to be sure to configure async io to get the full performance benefit. On some systems you have to manually configure both the OS and Oracle to use async and on others Oracle will automatically use async io if the file is a raw partiton. Check your platform specific manuals.

--
Mark D. Powell -- The only advice that counts is the advice that  you follow so follow your own advice --

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Share what you know. Learn what you don't. Received on Wed Aug 11 1999 - 09:24:19 CDT