Cause
An attempt was made to acquire a DDL lock that is already locked.
An attempt was made to acquire a DDL lock that is already locked.
This happens if you attempt to drop a table that has parse locks on it.
Try the following links for this error:
http://docs.oracle.com/cd/E16655_01/server.121/e26079/e0.htm
https://community.oracle.com/message/9316784
https://community.oracle.com/message/9446075
https://community.oracle.com/message/2025568
https://community.oracle.com/message/4497062
https://community.oracle.com/message/1117811
https://community.oracle.com/message/1228927
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