在oracle里面，如果有100条记录，排序后取出 第 10 行 到 第 20 行，用什么方法比较好？

SELECT * FROM (
SELECT table .* ,row_number() over(ORDER BY field) rk FROM table )WHERE rk>=10 AND rk<=20
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ROW_NUMBER
功能描述：返回有序组中一行的偏移量，从而可用于按特定标准排序的行号。
SAMPLE：下例返回每个员工再在每个部门中按员工号排序后的顺序号

SELECT department_id, last_name, employee_id, ROW_NUMBER()
       OVER (PARTITION BY department_id ORDER BY employee_id) AS emp_id
  FROM employees
WHERE department_id < 50;

DEPARTMENT_ID LAST_NAME                 EMPLOYEE_ID     EMP_ID
------------- ------------------------- ----------- ----------
           10 Whalen                            200          1
           20 Hartstein                         201          1
           20 Fay                               202          2
           30 Raphaely                          114          1
           30 Khoo                              115          2
           30 Baida                             116          3
           30 Tobias                            117          4
           30 Himuro                            118          5
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Oracle 9i 分析函数参考手册
http://www.cnoug.org/viewthread.php?tid=38387

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最简单的应该是
select b.* from
(select a.*,rownum rn from tablename order by col1) b
where b.rn>=10 and b.rn<=20