When a program unit refers to other database objects, it has considered dependent on that object.

When a program unit refers to other database objects, it has considered dependent on that object. If the referenced object is modified, the dependent object's status changes to INVALID, indicating it must be recompiled. Is it always a developer's responsibility to confirm the VALIDITY of the PL/SQL objects or should it be left to Oracle PL/SQL engine to validate the objects automatically? Provide an example to support your view.