Hameed, In looking at the tkprof output, no rows were fetched in any of the tests. This was after an even 1.2 *million* LIOs and all of this is just EXEC (rather than FETCH)? An LIO is extremely/fully CPU intensive and that is why your elapsed time is mostly taken up by cpu time. Was that a valid SQL? Also, it seems that this is a custom code. In any case, I would assume that with RAC_ON, the kernel would go through additional code to check cross-instance buffer status and hence you suffer additional CPU usage for the same number of LIOs. (I am not a RAC expert by any measure so take this with a big pinch of salt). John Kanagaraj <>< DB Soft Inc Phone: 408-970-7002 (W) Co-Author: Oracle Database 10g Insider Solutions http://www.amazon.com/exec/obidos/tg/detail/-/0672327910/ ** The opinions and facts contained in this message are entirely mine and do not reflect those of my employer or customers ** -----Original Message----- From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Hameed, Amir Sent: Thursday, March 09, 2006 1:54 PM To: john d parker; oracle-l@xxxxxxxxxxxxx; racdba-bounce@xxxxxxxxxxxxx Subject: RE: Job taking longer with more RAC nodes This is an Oracle 11i application 11.5.9) and the database version is 9.2.0.6 (64-bit). The thing that is surprising me is that there are no RAC specific waits. It is the CPU usage that is going high. I am sure there is an explanation to this and that is what I am trying to find out. -----Original Message----- From: john d parker [mailto:orclwzrd@xxxxxxxxx] Sent: Thursday, March 09, 2006 4:35 PM To: Hameed, Amir; oracle-l@xxxxxxxxxxxxx; racdba-bounce@xxxxxxxxxxxxx Subject: Re: Job taking longer with more RAC nodes Do you have any degree of parallelism? or is parallel degree set to default? In general, A well behaved app will perform approx the same on RAC maybe even marginally slower. A poorly behaved app will absolutely stink when moved to RAC. RAC is not a performance enhancing solution. John --- "Hameed, Amir" <Amir.Hameed@xxxxxxxxx> wrote: > Folks, > I need some help in understanding why a job is taking longer when it > is run in multiple nodes under RAC versus a single node in RAC and > with RAC disabled. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -- //www.freelists.org/webpage/oracle-l -- //www.freelists.org/webpage/oracle-l