if your in 9i, there is a really good article by arup nanda http://www.dbazine.com/nanda1.html its about 2 new view that help you drill down to the object for wait events. I found it helpful. > > From: Hemant K Chitale <hkchital@xxxxxxxxxxxxxx> > Date: 2004/03/09 Tue AM 07:05:24 EST > To: oracle-l@xxxxxxxxxxxxx > Subject: Re: can huge updates cause locks > > > As you have not provided information on what your findings [StatsPack, > WaitStats, utlbstat/utlestat, > sar, vmstat ... anything ...] were during that Peak Period, I believe > that you might be speculating about the "ITL Waits and Latch Misses". > > ITL Waits would manifest as "buffer busy wait". "Latch Misses", of course, > or waits on "latch free" -- but you need to drill down to find which latch. > > You might have been waiting on an Enqueue -- one or a few critical rows > locked by a user and everyone else waiting on him. > > The LGWR might have been waiting on Database Checkpoints and reporting > "unable to allocat new log" messages in the alert.log. Then, again, it might > have been waiting for the Archiver to archive out the redo logs it has already > switched out of before reusing them. > > These are the possible reasons which spring to mind immediately. There > could very well be many others. > Hemant > At 12:28 PM 09-03-04 +0530, you wrote: > >Yes ,I am sure they do,so do I .But my question was "ON PEAK TIME" when > >all the users are accessing this table.I tried this yesterday during peak > >load > >(simulated) around 6.10 avg on the said box and the system became slow as a > >snail.Plz read the last line I mentioned "IS THERE ANYTHING I AM MISSING".If > >you know that plz tell me. > >Deep > > > > > > What is your "hypothetical" explanation for why a single user with a > > > 5000 row update causes ITL Waits and Latch Misses and "slowly but surely > > > cripple the system" ? Are you sure about the "surely" ? > > > > > > A 5000 row update isn't necessarily going to cripple your system. > > > Many people run xthousands of rows updates frequently on databases. > > > > > > Hemant > > > At 04:24 PM 08-03-04 +0530, you wrote: > > >>Hi, > > >>First of all let me clarify this is a Hypothecal Situation. > > >>Suppose there is a table x which houses important piece of transaction > > >> data.Now this box happens to be a HP-UX 11.11,Dual Proc,4GB RAM Oracle > > >> 9.2.0.1 Box having 200 users.Now say one of the users suddenly at peak > > >> load period starts updating this table with 5000 new rows,my idea is it > > >> will cause immediate ITL Waits,Latch Misses and slowly but surely > > >> cripple the system.As the ITL waits will have a rippling effect I would > > >> expect ORA-60 to turn up in the alert<sid>.ora . > > >> > > >>Will you plz let me knw if I am correct or there is something I am > > >> missing alltogether. > > >>Thanks > > >>Deep > > >> > > >> > > >>---------------------------------------------------------------- > > >>Please see the official ORACLE-L FAQ: http://www.orafaq.com > > >>---------------------------------------------------------------- > > >>To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx > > >>put 'unsubscribe' in the subject line. > > >>-- > > >>Archives are at //www.freelists.org/archives/oracle-l/ > > >>FAQ is at //www.freelists.org/help/fom-serve/cache/1.html > > >>----------------------------------------------------------------- > > > > > > Hemant K Chitale > > > Oracle 9i Database Administrator Certified Professional > > > http://hkchital.tripod.com {last updated 24-Jan-04} > > > "If you wish to leave your footprints on the sand, do not drag your > > > feet" > > > > > > ---------------------------------------------------------------- > > > Please see the official ORACLE-L FAQ: http://www.orafaq.com > > > ---------------------------------------------------------------- > > > To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx > > > put 'unsubscribe' in the subject line. > > > -- > > > Archives are at //www.freelists.org/archives/oracle-l/ > > > FAQ is at //www.freelists.org/help/fom-serve/cache/1.html > > > ----------------------------------------------------------------- > > > > > > > >---------------------------------------------------------------- > >Please see the official ORACLE-L FAQ: http://www.orafaq.com > >---------------------------------------------------------------- > >To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx > >put 'unsubscribe' in the subject line. > >-- > >Archives are at //www.freelists.org/archives/oracle-l/ > >FAQ is at //www.freelists.org/help/fom-serve/cache/1.html > >----------------------------------------------------------------- > > Hemant K Chitale > Oracle 9i Database Administrator Certified Professional > http://hkchital.tripod.com {last updated 24-Jan-04} > "If you wish to leave your footprints on the sand, do not drag your feet" > > ---------------------------------------------------------------- > Please see the official ORACLE-L FAQ: http://www.orafaq.com > ---------------------------------------------------------------- > To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx > put 'unsubscribe' in the subject line. > -- > Archives are at //www.freelists.org/archives/oracle-l/ > FAQ is at //www.freelists.org/help/fom-serve/cache/1.html > ----------------------------------------------------------------- > ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------