The WITH OBJECT IDENTIFIER specifies the attributes of the object type that will
be used as a key to identify each row in the object view. In most cases, these attributes
correspond to the primary key columns of the base table. The specified attributes must
be unique and identify exactly one row in the view. If the object view is defined on an
object table or an object view, this clause can be omitted or WITH OBJECT IDENTIFIER
DEFAULT can be specified. In each case, we have specified the primary key of the
corresponding base table to provide uniqueness.