Ashoke,
Did you check what your top most wait events have been after the upgrade?
Direct path read behavior has changed drastically in 11.2, we were back to
normal BAU performance after setting optimizer_features_enable to 10g.
Why didn't you upgrade your DB to the latest 11g patchset 11.2.0.4, it has
all the bug fixes for 11.2?
Thanks,
Harinder Singh
On Mon, Oct 19, 2015, 14:22 Mandal, Ashoke <ashoke.k.mandal@xxxxxxxxxxxxx>
wrote:
Greetings All,
After the upgrade of one of my databases from Oracle 10.2.0.4 to Oracle
11.2.0.3 the users are experiencing poor query performance. The response
time of the queries have increased by 15 times.
I have tried the following without any luck but checking if you have any
other suggestions
1. Changed optimizer_dynamic_sampling from 2 to 1 => No performance
improvement
2. Changed optimizer_features_enable to '10.2.0.4' => No performance
improvement
3. Try setting cursor_sharing to force => No performance improvement
4. Set “_optimizer_skip_scan_enabled" = FALSE => No performance
improvement
Please let me know if you any suggestions to resolve this issue
Appreciate your help in advance,
Ashoke
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