WITH t(seq1, seq2, dt1, dt2) AS
(
          SELECT 170420, '201411001', '2015-10-12 12:11:58.000', null
UNION ALL SELECT 170422, '201411001', null, '2015-10-12 12:12:31.000'
UNION ALL SELECT 174566, '201411001', '2015-10-15 14:26:46.000', null
UNION ALL SELECT 174708, '201411001', null, '2015-10-15 15:47:18.000'
UNION ALL SELECT 174731, '201411001', '2015-10-15 15:53:14.000', null
UNION ALL SELECT 174733, '201411001', null, '2015-10-15 15:53:42.000'
UNION ALL SELECT 170252, '201411006', '2015-10-12 08:51:00.000', null
UNION ALL SELECT 170310, '201411006', null, '2015-10-12 10:22:09.000'
UNION ALL SELECT 170423, '201411006', '2015-10-12 12:14:16.000', null
UNION ALL SELECT 170482, '201411006', null, '2015-10-12 12:50:18.000'
)
SELECT seq1
     , seq2
     , dt1
     , LEAD(dt2) OVER(ORDER BY seq2, seq1) dt2
  FROM t
;

정확히 알려주셔서 감사합니다.

완벽 해결되었습니다