ORA-01732 during RCU schema creation due to "_simple_view_merging" set to FALSE

Scenario: 

Repository Creation Utility (RCU 11.1.1.6.0) was invoked in an 11.2.0.3.0 database to create repository schemas for SOA Infra.

The schema creation was erroring out all the time because of ORA-01732 error. Gathered extended trace in RCU level using following command
export RCU_LOG_LEVEL=TRACE  (default is ERROR). Still the log files were of not much help

INCIDENT_ERROR rcu: oracle.sysman.assistants.rcu.backend.action.ActionThread::run: Failed to execute method:  Excepton:
java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at oracle.sysman.assistants.rcu.backend.action.ActionThread.run(JavaAction.java:495)
        at java.lang.Thread.run(Thread.java:662)
Caused by: java.sql.SQLSyntaxErrorException: ORA-01732: data manipulation operation not legal on this view

Reason: 

Performance Team changed the value of an undocumented parameter, "_simple_view_merging" to FALSE (default is TRUE)

Impact:  

Setting the parameter _simple_view_merging to FALSE is equivalent to using the NO_MERGE hint against the view. Since we anticipated that it has to do some thing with the View merging, we concentrated on the parameters that were modified from its default value.
A support note (Doc ID 886790.1) too gave a hint on this direction.

Solution:

We then modified the parameter in one of the eight instances of the Exadata Full rack and succesfully created RCU schemas by pointing only to the instance where it was restarted. 

alter system set "_simple_view_merging"=TRUE SID='ORCL1';


The parameter was then modified in all RAC instances after performance team confirmed that there was no impact on performance after the change.