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?
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.
Assistance is Futile...
Re: redo contention-Urgent
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
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.
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