ORA-43557
Cannot perform this DDL operation on table 'string': a notification directive exists on this table or one of its dependent JSON-relational duality views
Cause
An attempt is being made to perform one of the disallowed DDLs on a table with a notification directive on itself or one of its dependent JSON-relational duality views.
Action
Drop all notification directives on this table or its JSON-relational duality views if you want to perform this DDL operation on the table.