Steve Robin wrote:
> On 17 Oct, 16:55, DA Morgan <damor..._at_psoug.org> wrote:
>> Steve Robin wrote:
>>> Hi,
>>> Two days before performance was down.... I find that log file sync and
>>> redo allocation latch was high.... now is there any way to find which
>>> queries or session were generating so many redo.
>>> Thanks
>>> Oracle : 9.2
>>> Server : Solaris
>> Define "log file sync and redo allocation latch was high."
>>
>> Compared to a baseline or just a big number and you are assuming that
>> it indicates an issue?
>> --
>> Daniel A. Morgan
>> University of Washington
>> damor..._at_x.washington.edu (replace x with u to respond)
>> Puget Sound Oracle Users Groupwww.psoug.org
>
> Daniel,
>
> I had given the values with log sync, about redo allocation.
> Latch Name Requests Misses Sleeps
> Sleeps 1->4
> ------------------Problem Performance
> redo allocation 19,830,541 32,005 25
> 31980/25/0/0
> /
> 0
> -------------------Right Performation
> redo allocation 19,813,484 72,544 4
> 72540/4/0/0/
>
> 0
>
> as well as I found following latch in problematic report which was not
> in right report.
>
> mostly latch-free SCN 23,251 190 1
> 189/1/0/0/0
>
> Please suggest.
>
> Thanks
My suggestion would be that these numbers, in and of themselves,
indicate nothing. Do you have anyone you can work with that knows
how to use StatsPack for tuning? This usenet group is not the place
to teach an ad hoc tuning class and I've yet to see any indication
that you actually have an issue. Not that you don't but "performance
was down" is not very precise.
--
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu (replace x with u to respond)
Puget Sound Oracle Users Group
www.psoug.org
Received on Wed Oct 17 2007 - 14:52:20 CDT
