Re: some one has experiece using direc io in nt, not using raw disks

 Thanks Vladimir

Oracle Performance Tuning Oracle course says "On some operating systems, such as Windows NT, Oracle Server process does not use o/s file system cache i/o operations. In this cases, use of raw devices may not show significant performance gains" I found a test, and there was some improvement using raw files.

As I understand what you say is
it is a good idea to use direct io in NT, without raw files.? Or I'm wrong?  

-------Original Message-------  

From: oracle-l_at_freelists.org
Date: 07/05/04 17:31:57
To: oracle-l_at_freelists.org
Subject: Re: some one has experiece using direc io in nt, not using raw disks  

Juan Carlos Reyes Pacheco wrote:
> Hi List,
> Some one has experiece using direc io in nt, not using raw disks, I read
> this don't gives as much performance as in other platforms.
 

Oracle9i Database Getting Started, Release 2 (9.2) for Windows Part Number A95490-01  

2 Oracle9i Windows/UNIX Differences  

Direct Writes to Disk  

On both UNIX and Windows platforms, bypassing the file system buffer cache ensures data is written to disk.  

On UNIX, Oracle uses the O_SYNC flag to bypass the file system buffer cache. The flag name depends on the UNIX port.  

On Windows, Oracle bypasses the file system buffer cache completely.

--
Vladimir Begun
The statements and opinions expressed here are my own and
do not necessarily represent those of Oracle Corporation.
 
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