performance issue after upgrade from 10.2.0.5 to 11.2.0.2
- From: Pawel Smolarz <pawel.smolarz@xxxxxxxxxx>
- To: ORACLE-L <oracle-l@xxxxxxxxxxxxx>
- Date: Tue, 30 Aug 2011 12:05:03 +0200
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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