The UNION, EXCEPT, MINUS, and INTERSECT operators can be followed
    by the keyword CORRESPONDING. This causes the two select lists of
    the select-merge-clause to be compared by name. Only those column
    names which appear in both lists are retained for the resulting
    query table.

    The name is either the column name, or the name provided by
    the AS clause. If there are no names in common, or a column
    name appears more than once in a select list then an error is
    reported.