1  –  CASCADE

    Specifies that you want SQL to invalidate all objects that
    refer to routines in the module and then delete that module
    definition. This is known as a cascading delete. If you delete a
    module referenced by a stored routine with a routine or language-
    semantic dependency, SQL also marks the affected stored routine
    as invalid.

2  –  IF_EXISTS

    Prevents SQL command language from displaying error messages if
    the referenced object does not exist in the database.

3  –  module-name

    Identifies the name of the module.

4  –  RESTRICT

    Prevents the removal of a stored routine definition when the
    function or procedure is referenced by any other object within an
    Oracle Rdb database. RESTRICT is the default.