ORACLE分頁查詢SQL語句(最有效的分頁)

1.無ORDER BY排序的寫法。(效率最高)
(經過測試，此方法成本最低，只嵌套一層，速度最快！即使查詢的數據量再大，也幾乎不受影響，速度依然！)

SELECT *

  FROM (SELECT ROWNUM AS rowno, t.*

          FROM emp t

         WHERE hire_date BETWEEN TO_DATE ('20060501', 'yyyymmdd')

                             AND TO_DATE ('20060731', 'yyyymmdd')

           AND ROWNUM <= 20) table_alias

 WHERE table_alias.rowno >= 10;

 

2.有ORDER BY排序的寫法。(效率較高)
(經過測試，此方法隨着查詢范圍的擴大，速度也會越來越慢哦！)

SELECT *

  FROM (SELECT tt.*, ROWNUM AS rowno

          FROM (  SELECT t.*

                    FROM emp t

                   WHERE hire_date BETWEEN TO_DATE ('20060501', 'yyyymmdd')

                                       AND TO_DATE ('20060731', 'yyyymmdd')

                ORDER BY create_time DESC, emp_no) tt

         WHERE ROWNUM <= 20) table_alias

 WHERE table_alias.rowno >= 10;