Oracle Error Message
ORA-30756: cannot create column or table of type that contains a supertype attribute
Reason for the Error
The user tried to create a column or table of an object type that contains a supertype attribute. This is not supported because it leads to infinite recursion in our current storage model. Note that creating a column of a type implies that we create columns corresponding to all subtype attributes as well.
Solution
Change the type definition to contain a supertype REF attribute instead of the supertype object attribute.
