Re: Q: does DirectIO on windows is supported on file systems ?

From: Niall Litchfield <niall.litchfield_at_gmail.com>
Date: Fri, 24 Jun 2005 08:54:21 +0100
Message-ID: <7765c89705062400541b8434b@mail.gmail.com>

On 6/23/05, Sunil Bhola <oraclebhola_at_yahoo.com> wrote:
>
> Hi Paul,
> Thanks for correcting me. But I forget to speicify that the Professional
> Windows with NTFS File System dont have file system buffer cache. Correct me
> if I am wrong.
> Regards,
>

You're wrong! Check out task manager and the performance tab, that figure for System Cache is the filesystem cache that is currently allocated. See http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wmisdk/wmi/win32_perfformatteddata_perfos_cache.aspfor the management instrumentation details and a description of what the 'System Cache' really is.
I'm not quite sure what Paul means about turning off the filesystem cache for Oracle systems, I guess you'd gain a little more RAM to devote to Oracle, but Oracle on Win32 performs DirectIO anyway. --
Niall Litchfield
Oracle DBA
http://www.niall.litchfield.dial.pipex.com

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Received on Fri Jun 24 2005 - 03:59:34 CDT