SELECT x1, f2, f3, x2, x3 FROM ( SELECT f1 AS x1,f2,f3,f4 as x2, (f4= f5) as x3 FROM Some_table_2006) UNION (SELECT f1 AS x1,f2,f3,f4 as x2, (f4= f5) as x3 FROM Some_tabel_2007)) As Tbl1 ;