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Re: perforamance issue

From: Mladen Gogala <>
Date: Sun, 01 Oct 2006 22:41:55 -0400
Message-id: <>

On 10/01/2006 09:45:48 PM, edwin devadanam wrote:
> Hi gurus,
> we are having oracle applications instance(11.5.10.) running with database version.
> After applying oracle applications patch(not database patch),the whole system turned upside down.
> All the quieries are taking 20 times more time than before patching.
> we have done some workarounds but invain.
> please have a look at the active users sql run on the database before and after applying patch.
> active users before patching : time taken to complete 10sec (please see attachement)
> active users after patch : time taken to complete 180sec (please see attachment)
> Any help would be appreciated.
> Thanks,
> Edwin.K

Edwin, there are several things:

  1. Do you have plans before the patch? What exactly does the patch do? What problem was the patch supposed to solve? What modules does it patch?
  2. What kind of the statistics do you have? Did you gather system statistics, aka "CPU costing"? Do you have all relevant histograms?
  3. Did you trace the sessions in question? 10046 and 10053? Are there any other changes in effect?
  4. Did the patch installation re-compute your statistics? Are there any new hints added to the application processes?
  5. What are the application waiting for? Sequential or scattered reads? Enqueues?
  6. Are performance problems centered around one group of applications? One table, package or trigger? Is there anything that the modules that users are complaining about have in common? Is every module using the same procedure, table or something like that?
  7. Did you open a level 1 SR with Oracle Corp? Your situation sounds like "business critical system down" situation and Oracle is usually very good when that happens.

It is extremely hard to give you a precise diagnosis based only on the several execution plans. The only person who can fix the things is you. This is why the job of database administrator is so stressful. Now everything depends on you, your knowledge and experience. If things fail, you will be blamed for everything and probably fired. I hope that I have lessened the level of stress that you feel right now.

Mladen Gogala

Received on Sun Oct 01 2006 - 21:41:55 CDT

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