EDN - Same Event triggered twice in Cluster Environments

In Cluster environments, during large number of business transactions, same Business Events triggers more than once, causes duplicate transaction.

To resolve below issue, please follow below steps:

1. Log in to the 11.2 database:
   CONNECT /AS SYSDBA
    
2. Specify the following SQL command in SQL*Plus to disable the 11.2 dequeue optimizations:
   SQL> alter system set event='10852 trace name context forever, level 16384'scope=spfile;
   
3. Restart the database.

Source: Metalink 1435312.1