WITH t AS
 (
 SELECT TO_DATE('201108011400', 'YYYYMMDDHH24MI') SDT, TO_DATE('201108011700', 'YYYYMMDDHH24MI') EDT FROM dual
 UNION
 SELECT TO_DATE('201108012000', 'YYYYMMDDHH24MI') SDT, TO_DATE('201108012359', 'YYYYMMDDHH24MI') EDT FROM dual
 )
SELECT
 FROM_DT
    ,TO_DT
FROM(
  SELECT
      LAG(EDT + 1/24) OVER(ORDER BY SDT ASC) AS FROM_DT
      ,SDT - 1/24 AS TO_DT
  FROM T
)WHERE FROM_DT IS NOT NULL
 

앞행 EDT와 SDT의 차이가 2시간 이상 난나는 가정하에 작성했네요..

더 멋진 쿼리는 다른분이 해 주실거에요.. ^^;;;;

한가지더 질문 드릴께염...

WITH t AS
 (
 SELECT TO_DATE('201108011000', 'YYYYMMDDHH24MI') SDT, TO_DATE('201108011300', 'YYYYMMDDHH24MI') EDT FROM dual
 UNION
 SELECT TO_DATE('201108011400', 'YYYYMMDDHH24MI') SDT, TO_DATE('201108011700', 'YYYYMMDDHH24MI') EDT FROM dual
 UNION
 SELECT TO_DATE('201108012000', 'YYYYMMDDHH24MI') SDT, TO_DATE('201108012359', 'YYYYMMDDHH24MI') EDT FROM dual
 )
SELECT
 FROM_DT
    ,TO_DT
FROM(
  SELECT
      LAG(EDT + 1/24) OVER(ORDER BY SDT ASC) AS FROM_DT
      ,SDT - 1/24 AS TO_DT
  FROM T
)WHERE FROM_DT IS NOT NULL
 

이렇게 조회할 경우 좀 틀리게 나오는데... 다른 방법은 없을까여??

SELECT from_dt
     , to_dt
  FROM (SELECT MAX(edt) OVER(ORDER BY sdt, edt
                ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING
                 ) + 1/24 from_dt
             , sdt - 1/24 to_dt
          FROM t
        )
 WHERE from_dt < to_dt
;