redo contention-Urgent

[portal]

Folks, I have a serious problem in production machine- as it became too slow and I found out there is contention in LGWR.
DataFile Name Result
---------------------------------------- ---------------
redo log space requests 2,017
It has to be around 0, so please advice me . My current log_buffer parameter in init.ora is 10MB and I have 5 redo log groups of 512 KB each.Oracle 9i rel2 on Windows.
If I increase the logbuffer and rebounce db is it going to solve, wondering more than 10MB will actually benefit or not?
Thanks

[waitecj]

10MB already sounds rather large to me, but then without any details on your database, how can I judge? So, can we see a 15 minute statspack report and possibly a session trace (set events with waits) so we can see what effect these redo log space requests are having? Thanks ever so.

[Telco_DBA]

Originally posted by portal
My current log_buffer parameter in init.ora is 10MB and I have 5 redo log groups of 512 KB each
Thanks

Hi Portal,

I agree with waitecj that the 10 MB log_buffer is very much (Logwriter starts writing in case of commit or if log_buffer is 1/3rd full or if log_buffer is 1 MB full)

And the 15-minutes statspack report requested by witecj is VERY important!

But are you sure that your redologs files are only 512 KB ??? - or did you mean 512 MB ?
10 MB log_buffer with 512 kb redo log file size is crazy.

(I used on my billing system redolog file size 1 GB (3 Groups, 2 members) and switched every 5 minutes during billing run)

How often are your log switches / how much redo do you write per minute / per hour ?

(The old rule was "about every 20 minutes")

At each redo log switch there occures a checkpoint, therefore 512 kb redo log file size seems to be the problem.

Good Luck,

Telco_DBA
http://www.Mercury-Consulting-Ltd.com