Some good inputs by Tanel Poder on how to tune latches on his blog: http://blog.tanelpoder.com/2008/07/23/advanced-oracle-troubleshooting-guide-part-8-even-more-detailed-latch-troubleshooting-using-latchprofx/ Regards, Jaffar On Wed, Oct 15, 2008 at 3:10 PM, Sriram Kumar <k.sriramkumar@xxxxxxxxx>wrote: > Hi Gurus, > We had started some online performance testing of our application on 11g ( > 11.1.0.7) . There seems to be a severe latching problem on kokc descriptor > latch. I understand that this is a new latch in 11g and not able to find > anything beyond that. The same test went fine on 10g R2. Metalink has no > hits on this have any one of you faced a similar problem in 11g and any > possible hints/undocumented parameters that can help? > > have copied relevant sections from AWR > > Top 5 Timed Foreground Events > > *Event* > > *Waits* > > *Time(s)* > > *Avg wait (ms)* > > *% DB time* > > *Wait Class* > > latch free > > 566,894 > > 184,570 > > 326 > > 93.68 > > Other > > DB CPU > > > > 10,676 > > > > 5.42 > > > > log file sync > > 76,340 > > 1,184 > > 16 > > 0.60 > > Commit > > library cache: mutex X > > 2,283,183 > > 360 > > 0 > > 0.18 > > Concurrency > > SQL*Net more data from client > > 105,660 > > 117 > > 1 > > 0.06 > > Network > > > > Latch Statistics > > > > Latch Name > > Get Requests > > Pct Get Miss > > Avg Slps /Miss > > Wait Time (s) > > NoWait Requests > > Pct NoWait Miss > > kokc descriptor allocation latch > > 3,968,130 > > 18.59 > > 0.88 > > 174283 > > 0 > > > > > > Latch Miss Source > > > > *Latch Name* > > *Where* > > *NoWait Misses* > > *Sleeps* > > *Waiter Sleeps* > > kokc descriptor allocation latch > > kokcdlt: regular free > > 0 > > 327,851 > > 265,626 > > kokc descriptor allocation latch > > kokcdlt: allocation > > 0 > > 321,646 > > 383,871 > > * * > Best Regards, > > Sriram Kumar > -- Best Regards, Syed Jaffar Hussain Oracle Certified Master (10g) http://www.oracle.com/technology/ocm/shussain.html Oracle ACE http://apex.oracle.com/pls/otn/f?p=19297:4:1579866181463918::NO:4:P4_ID:126 OCP 8i,9i & 10g DBA RAC Certified Expert Official Oracle RAC SIG Representative for Saudi Arabian region ( http://www.oracleracsig.org/) I blog at http://jaffardba.blogspot.com/ -------------------- "Winners don't do different things. They do things differently."