WITH t_a AS
(
SELECT LEVEL id
  FROM dual
 CONNECT BY LEVEL <= 31
)
, t_b AS
(
SELECT 2 id, 10 v, '08:00' tm FROM dual
UNION ALL SELECT  5, 13, '08:10' FROM dual
--UNION ALL SELECT 11, 11, '09:12' FROM dual
--UNION ALL SELECT 20, 13, '09:10' FROM dual
--UNION ALL SELECT 21, 12, '09:28' FROM dual
--UNION ALL SELECT 23, 12, '09:15' FROM dual
--UNION ALL SELECT 24, 10, '09:00' FROM dual
--UNION ALL SELECT 25, 13, '09:13' FROM dual
--UNION ALL SELECT 26, 13, '09:30' FROM dual
--UNION ALL SELECT 28, 10, '09:30' FROM dual
--UNION ALL SELECT 29, 11, '09:30' FROM dual
)
SELECT id
     , v
     , tm
     , DECODE(ROWNUM, 1, 'O') last_flag
  FROM (SELECT a.id
             , b.v
             , b.tm
          FROM t_a a
             , t_b b
         WHERE a.id = b.id(+)
         ORDER BY b.tm DESC NULLS LAST
             , NVL2(b.id, -a.id, a.id)
        )
 WHERE ROWNUM <= 9
 ORDER BY tm, id
;

마농님 감사합니다 딱 원하던대로 나오네요