Re: Awr waits over 100%
From: Marcus M�nnig <mm_at_marcusmoennig.de>
Date: Wed, 28 Sep 2011 17:45:20 +0200
Message-ID: <CAFuw4v=dxCoLr7C_PeB=-1w9bbdF4AsB1yqON+S=PqEMKROeJQ_at_mail.gmail.com>
(Resending due to overquoting...)
Date: Wed, 28 Sep 2011 17:45:20 +0200
Message-ID: <CAFuw4v=dxCoLr7C_PeB=-1w9bbdF4AsB1yqON+S=PqEMKROeJQ_at_mail.gmail.com>
(Resending due to overquoting...)
While your client session/process waits for "log file sync" when comitting, the LGWR process does the work of writing out the log buffer to disk and waits for "log file parallel write". "log file parallel write" wait events happen during the "log file sync" wait event, so there is some double counting taking place.
Tony Hasler explained this very nice in his three blog posts here:
http://tonyhasler.wordpress.com/2011/07/24/log-file-sync-and-log-file-parallel-write-part-1/
Cheers,
Marcus
-- http://www.freelists.org/webpage/oracle-lReceived on Wed Sep 28 2011 - 10:45:20 CDT