Performance Issue With High CPU Usage After Upgrade to 12c RDBMS (Doc ID 2139151.1)

Last updated on MAY 31, 2016

Applies to:

Oracle Database - Enterprise Edition - Version 12.1.0.2 and later
Exadata X5-2 Full Rack - Version All Versions to All Versions [Release All Releases]
Information in this document applies to any platform.

Symptoms

Performance issue after Database upgraded to 12c.
Customer upgraded from 11g to 12c.

All the queries are taking multifold time after upgrade, compared to previous version. No change in the underlying hardware or any other parameters.

 

AWR report Analysis:

Increased DB CPU (For example, in a customer case it is 5,374sec to 20,705sec for 1 hour duration)
All other waits are fairly similar.

Number of parses (Hard and Soft) are similar between the 2 versions.

 

Changes

RDBMS upgrade to 12.1.0.2.

Cause

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