Cause
PARALLEL clause cannot be empty.
PARALLEL clause cannot be empty.
specify any combination of DEGREE { <n> | DEFAULT } and INSTANCES { <n> | DEFAULT } within the PARALLEL clause.
Try the following links for this error:
http://docs.oracle.com/cd/E16655_01/server.121/e26079/e12700.htm
https://community.oracle.com/message/3191809
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