Re: Very high 'log file sync' wait time with no 'log file parallel write' wait time

I haven't followed this closely, but if you're seeing lots of waits for log file sync, but no waits for log file writes, then

1. There used to be a bug in 9i which did not report the timing of log file writes properly - it's possible that this has slipped into your version of 10g.

OR

b) somehow your log file writer is using a variant of asynchronous I/O, so the log writer is dispatching a write request and sending an ACK to the front-end without
having to wait for the write to complete.

-- 
Regards

Jonathan Lewis
http://jonathanlewis.wordpress.com

Author: Cost Based Oracle: Fundamentals
http://www.jlcomp.demon.co.uk/cbo_book/ind_book.html

The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html


<mccmx_at_hotmail.com> wrote in message 
news:1164783964.591310.257610_at_16g2000cwy.googlegroups.com...


>> Are your logs on different mounts?  Are you on RAID-5.  Is it Direct

>> Path, looks like not.

>> I hope you don't have your windows page file on the same volume as the

>> redo.

>

> What makes you so sure it is an I/O problem - I've already said that we

> are seeing no waits for 'log file parallel write', which suggest that

> log file I/O is not the problem..

>

> Matt

>