Re: LGWR and DBWR

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Wed, 27 Feb 2008 20:54:04 -0000
Message-ID: <4JGdnQpf9Op4UFjanZ2dnUVZ8tmhnZ2d@bt.com>


"Dereck L. Dietz" <dietzdl_at_ameritech.net> wrote in message news:Xbpwj.12475$J41.2392_at_newssvr14.news.prodigy.net...
> Oracle 10.2.0.3.0
> Windows 2003 Server
>
> Is it possible for improperly sized redo log files to be overwhelmed to
> the point where it will cause a process which is performing a lot of
> writes to multiple tables to stop processing without any error or reason
> in a log file?
>

There is a flaw in that question.
What do you mean by the process "stopped" ?

Do you really mean that the process seems to have stopped because it takes much longer than you expect ?

Have you checked v$session_wait and v$session_event for the process to see where it is accumulating time (if it is still alive).

If the log files are very small and lgwr and dbwr are having trouble keeping up with the workload, the session might spend a lot of time waiting on
  log buffer space
  log file sync
  write complete wait
and various waits relating to checkpoint incomplete (but, as another poster pointed out, these would be recorded in the alert log).

-- 
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
Received on Wed Feb 27 2008 - 14:54:04 CST

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