这个SQL怎么优化

这个SQL如何优化？

SQL code

SELECT * FROM (SELECT A.PDATE,A.FLIGHT_NO,A.CARRIER,A.ARR_AIRPORT,A.DEPT_AIRPORT,A.Delay_Time,A.APT_Delay_Time,A.REMARK, ROWNUM RN FROM (SELECT * from T_UNUSUATest CINNER JOIN THIS_TABLE1  B ON C.LEG_ID=B.LEG_ID) A WHERE ROWNUM <=10  AND PDATE between '2011-07-25' AND '2011-07-28'AND FLIGHT_NO_DISP like '%U%' AND ARR_AIRPORT='PVG' Order By PDATE)WHERE RN >= 1

SQL code

SELECT *  FROM (SELECT A.PDATE,               A.FLIGHT_NO,               A.CARRIER,               A.ARR_AIRPORT,               A.DEPT_AIRPORT,               A.Delay_Time,               A.APT_Delay_Time,               A.REMARK,               ROWNUM RN          FROM (SELECT *                  from T_UNUSUATest C                 INNER JOIN THIS_TABLE1 B ON C.LEG_ID = B.LEG_ID) A         WHERE ROWNUM <= 10           AND PDATE between '2011-07-25' AND '2011-07-28'           AND FLIGHT_NO_DISP like '%U%'           AND ARR_AIRPORT = 'PVG'         Order By PDATE) WHERE RN >= 1没啥子优化的了
[解决办法]
SQL code
--粗略的估计你的执行计划，按照下面的改法试试SELECT *  FROM (SELECT A.PDATE,               A.FLIGHT_NO,               A.CARRIER,               A.ARR_AIRPORT,               A.DEPT_AIRPORT,               A.DELAY_TIME,               A.APT_DELAY_TIME,               A.REMARK,               ROWNUM RN          FROM (SELECT *                  FROM T_UNUSUATEST C, THIS_TABLE1 B                 WHERE ARR_AIRPORT = 'PVG'                   AND C.LEG_ID = B.LEG_ID                   AND PDATE BETWEEN '2011-07-25' AND '2011-07-28') A         WHERE ROWNUM <= 10 ISP LIKE '%U%'         ORDER BY PDATE) WHERE RN >= 1
[解决办法]
------------------------------
给 PDATE 建立index
SELECT *
 FROM (SELECT A.PDATE,
              A.FLIGHT_NO,
              A.CARRIER,
              A.ARR_AIRPORT,
              A.DEPT_AIRPORT,
              A.DELAY_TIME,
              A.APT_DELAY_TIME,
              A.REMARK,
              ROWNUM RN
         FROM (SELECT *
                 FROM T_UNUSUATEST C, THIS_TABLE1 B
                WHERE ARR_AIRPORT = 'PVG'
                  AND C.LEG_ID = B.LEG_ID
                  AND PDATE BETWEEN '2011-07-25' AND '2011-07-28'
                  AND ISP LIKE '%U%'
                ORDER BY PDATE) A
        WHERE ROWNUM <= 10  
        )
  WHERE RN >= 1
--------------------------------------------


[解决办法]
贴出你的执行计划吧，没有执行计划的话，先按照我写的那个方法试试看。
[解决办法]
探讨


贴出你的执行计划吧，没有执行计划的话，先按照我写的那个方法试试看。