Bug #46900 [innodb:aio:windows] documentation of innodb_flush_method needs to be corrected

• Submitted: 24 Aug 2009 19:21
• Modified: 1 Sep 2009 17:32
• Reporter: Inaam Rana
• Status: Not a Bug
• Category: MySQL Server: Documentation
• Severity: S3 (Non-critical)
• Version: 5.0, 5.1, 5.4
• OS: Any
• Assigned to: Paul DuBois
• CPU Architecture: Any

[24 Aug 2009 19:21] Inaam Rana

Description:
acceptable values for innodb_flush_method on windows need to be updated.

http://dev.mysql.com/doc/refman/5.1/en/innodb-parameters.html#sysvar_innodb_flush_method says:

<snip>
On Windows, the flush method is always async_unbuffered and cannot be changed. 
</snip>

This should be changed to something like:

On Windows following values are legitimate:
1) 'normal' Implies normal buffered IO
2) 'unbuffered' Implies non-buffered IO i.e.: FILE_FLAG_NO_BUFFERING flag is used at file create/open time.
3) 'aysnc_unbuffered' This is default and recommended value. This value means that native AIO interface is used on Windows and IO operations are unbuffered i.e.: FILE_FLAG_OVERLAPPED and FILE_FLAG_NO_BUFFERING are used at file create/open time.

How to repeat:
see above

[24 Aug 2009 19:24] Valeriy Kravchuk

Thank you for the documentation request.

[1 Sep 2009 17:32] Inaam Rana

Actually these options are kept undocumented on purpose. On windows native AIO has worked without any issues. Closing this as not a bug.