特殊需求下Oracle分頁的加速

來源:互聯網
上載者:User

Oracle分頁大家一般使用這種形式
  SELECT * FROM
  (
  SELECT A.*, rownum r
  FROM
  (
  SELECT *
  FROM Articles
  ORDER BY PubTime DESC
  ) A
  ) B
  WHERE r <= PageUpperBound
  and r > PageLowerBound;
  在很多時候,並不需要排序,而是要進行多表的聯查計算等,這個時候資料多了就會顯的很慢
  發現慢就慢在Order By上
  更改如下:
  SELECT * FROM
  (
  SELECT A.*, rownum r
  FROM
  (
  SELECT *
  FROM Articles
  ) A
  WHERE rownum <= PageUpperBound ORDER BY PubTime DESC //Order by 放這來
  )B
  and r > PageLowerBound;

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