You have to be more precise describing what slowed down. What is your = way of measuring the application response time? Is the app running on the server hosting the DB?=20 That table that you re-organized, is it being accessed using indexes? Waleed -----Original Message----- From: zhu chao [mailto:chao_ping@xxxxxxxxxxx] Sent: Friday, April 30, 2004 5:42 AM To: oracle-l@xxxxxxxxxxxxx Subject: CPU upgrade caused application slow down Hi, list friends: =20 We did a server upgrade this month. And we hit something we cannot = understand. So we refer to you guys for help , hoping you have similar = experienceJ We did a server upgrade this month. Biddb upgrade from = 8*900MHZ FireV880 to 8*1200MHZ Fire V880, SAN HBA card also upgraded = from 1gb to 2gb. System Level parameter like /etc/system, oracle initsid.ora = are same for biddb before and after server upgrade.(except for processes = increased from 800 to 1200).SGA of database is reduced from 11.5GB to = 11GB.But disk read did not increase as we reorganized a table with 29M = records to 13M records(CTAS, drop old table). The upgrade result is good, CPU usage dropped = about 20%-30% percent. But the application response time does not drop. = It even slow down slightly. :(. This is not what we expect. Statspack = does not show much difference before and after upgrade(load profile , = wait event etc). Later we did some test, hoping to find out how can this = happen, but we cannot draw a conclusion from our test result. 1.. According to Cary Millsap=A1=AFs theory, upgrade CPU *CAN* make = performance worse. In his case, SQL*Net was the bottleneck. Our server = network traffic is only at 15-20Mb/Second. This seems not like the = bottleneck, Though from 10046 trace report, sqlnet wait is the NO.1 wait = event, but this is normal for most applications. I also tried to change = the tnsnames.ora and listener.ora with larger SDU/TDU of 8KB, restarted = tuxedo service and oracle listener. And compare the performance data = leter. This does not make much difference for application response time. = 2.. We did some pure simple SQL test. Result in appendix 1. SAME SQL = in 1200MHZ CPU does run faster.=20 =20 2.. We write a simple tuxedo service run the same SQL for 1000 times. = Everytime the SQL is transferred through SQL*Net and result is fetched = into host variable. The result still shows that it runs faster on = 1200MHZ CPU. The average response time in 1200MHZ server is 12.12ms ,and = the average response time in 900mhz server is 14.20ms.=20 =20 We cannot find out the root cause of application slow down. Though the = slow down is very small (around 5% percent, maybe), it is not happy to = see such result and we are interested in knowing why. If you have similar experience before and do find out how this can = happen, we would be very happy. =20 Thanks for your time. Regards Zhu Chao. =20 =20 =20 Appendix 1: Eachdb2: (900mhz CPU) =20 1 declare v_result number; 2 begin 3 for x in 1..1000 loop 4 select count(*) into v_result from testsystem; 5 end loop; 6* end; 09:38:13 7 / =20 PL/SQL procedure successfully completed. =20 Elapsed: 00:02:17.37 09:40:31 SQL> =20 Biddb (1200MHZ CPU) =20 1 declare v_result number; 2 begin 3 for x in 1..1000 loop 4 select count(*) into v_result from testsystem; 5 end loop; 6* end; 09:42:29 SQL>=20 09:42:30 SQL>=20 09:42:30 SQL> / =20 PL/SQL procedure successfully completed. Elapsed: 00:01:57.99 ---------------------------------------------------------------- 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 -----------------------------------------------------------------