Cause
An ADD SUBPARTITION operation cannot be executed when a subpartition with DEFAULT values exists
An ADD SUBPARTITION operation cannot be executed when a subpartition with DEFAULT values exists
Cannot execute the command, unless two or more values exist for subpartition
Try the following links for this error:
http://docs.oracle.com/cd/E16655_01/server.121/e26079/e12700.htm
https://community.oracle.com/message/1124737
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