Re: performance issue after upgrade from 10.2.0.5 to 11.2.0.2

From: <verma.labs_at_gmail.com>
Date: Tue, 30 Aug 2011 14:00:45 +0000
Message-ID: 2066149533-1314712876-cardhu_decombobulator_blackberry.rim.net-1052678197-_at_b12.c2.bise7.blackberry>

Hi, we did face the problem but its related with program code after that everything Works fine

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-----Original Message-----
From: Pawel Smolarz <pawel.smolarz_at_nordea.com> Sender: oracle-l-bounce_at_freelists.org
Date: Tue, 30 Aug 2011 12:05:03
To: ORACLE-L<oracle-l_at_freelists.org> Reply-To: pawel.smolarz_at_nordea.com
Subject: performance issue after upgrade from 10.2.0.5 to 11.2.0.2

Hi,
I upgraded database from 10.2.0.5 to 11.2.0.2.2 on AIX 5.3 platform without problem. Everything works perfectly. During performance testing we noticed much slower queries. We have two databases, one 10.2.0.5 and 11.2.0.2. Both databases are the same (data and parameters). The first 10g based on physical lun, second 11g based on snapshot from physical lun. After investigation I found that 11g execution plan is different than on 10g. OK. No problem. I saved execution plan from 10g (sqlset) and loaded to 11g, and on both databases execution plan is the same.

But. On 11g I see that optimizer prefers sequential read and db direct read than scattered read (10g). This causes the query execution time is longer- ~ 4x. Maybe the reason is snapshot??. We solved this problem by setting the events '10949', but maybe someone knows where is the cause.

--
Pozdrawiam / Regards,
Paweł Smolarz

Nordea Bank Polska S.A. z siedzibą w Gdyni, ul. Kielecka 2, 81-303 Gdynia, wpisaną do Rejestru Przedsiębiorców Krajowego Rejestru Sądowego pod numerem: 0000021828, dla której dokumentację przechowuje Sąd Rejonowy Gdańsk - Północ w Gdańsku, VIII Wydział Gospodarczy Krajowego Rejestru Sądowego, o kapitale zakładowym i wpłaconym w wysokości: 277.493.500,00 złotych, NIP: 586-000-78-20, REGON: 190024711--
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