Vantage verifies that the structure of columns defined as foreign keys, or referenced by foreign keys, is not changed in any manner that violates the rules for the definition of a foreign key constraint.
An ALTER TABLE (or DROP INDEX) request attempting to change the structure of such a column aborts and causes the system to return an error to the requestor.
Vantage verifies that a table referenced by another is not dropped. Before dropping the table, you must perform an ALTER TABLE request to drop the foreign key reference.