Listing 6: U EXCEPT ALL V Query
SELECT col1, col2
FROM (SELECT col1, col2, SUM(cnt) as dups
      FROM (SELECT col1, col2, COUNT(*) AS cnt
            FROM U
            GROUP BY col1, col2
     
            UNION ALL
           
            SELECT col1, col2, -COUNT(*)
            FROM V
            GROUP BY col1, col2) AS D1
      GROUP BY col1, col2
      HAVING SUM(cnt) > 0) AS D2
  JOIN Nums
    ON n <= dups