Re: log writer check

On 23 May 2005 09:17:21 -0700, "Eugene" <epipko_at_hotmail.com> wrote:

>Hi all,
>I have noticed that REDO LOG WRITER is taking very long time. It took
>150 ms to write to a datafile.
>I have 12 groups with 2 members in each. How do I go about it? What do
>I check? Is there a way to see what caused it?
>
>
>Thanks,
>Eugene

LGWR doesn't write datafiles, and the ARC<n> process is responsible for archiving a log file, so you seem to mix up things. Twelve groups is a bit ridiculous. Usually 4 or 5 are sufficient. How big are these log files?
Also, if you run only *one* archiver, and several online redologs needs to be archived at the same time you have a bottle neck. As you have 12 online redolog groups, it very much looks like you have a badly written application, and you already resorted to 'more=better' tuning.
You can increase the number of max_archive_processes (top of my head, you'll need to look this up), but I think you would better start beating developers.

--
Sybrand Bakker, Senior Oracle DBA