Re: Raw usage in Solaris

Hi, Nuno,

You don't need Veritas or SDS to use raw. In fact, if you do, that's not called raw any more. To allow oracle to read from the raw device, run chown oracle:dba [thedevice] as root.

Direct I/O may speed up or slow down db file read depending on whether the file is sequentially read (at OS or filesystem level). Filesystem page cache helps a lot by prefetch if the read is sequential. But using direct I/O allows you to give the memory that otherwise would be part of page cache to Oracle buffer cache, which manages Oracle data caching more intelligently. Read Steve Adams' Ixora News - March 2002 newsletter.

Yong Huang
yong321_at_yahoo.com Received on Tue May 14 2002 - 12:06:19 CDT