Php+MySql分页机制两种方案的比较测试：

mysql|比较|分页

硬件环境：PIII550,128M,15.2G
软件环境：Win98+Apache+Php4+MySql

方案一：
  1.第一次查询时用Select count(1) from tab where condition 取得满足条件的记录数$rows
  2.通过前页数$page，每页记录数$rpp取回记录集
    select * from tab where condition limit ($page-1)*$rpp,$rpp
  3.显示返回记录集的所有记录。
  4.页面转移时将$rows传递给以后页面。

方案二：
  1.取回满足条件的记录集
    select * from tab where condition
  2.移动指针到($page-1)*$rpp
  3.显示$rpp条记录

==============+======+==============================================+======+======+========
    记录数    | 方案 | 次数   1   2   3   4   5   6   7   8   9   0 | 平均 | 平均 | 效率比
==============+======+==============================================+======+======+========
              |      |第一页  2 , 1 , 1 , 2 , 1 , 1 , 2 , 2 , 1 , 2 |  1.3 |      |
              |  一  +----------------------------------------------+------+  1.6 |
10000条记录时 |      |其它页  2 ，2 , 2 , 3 , 1 , 1 , 2 , 2 , 2 , 2 |  1.9 |      | 4.8125
              +------+----------------------------------------------+------+------+
              |  二  |每一页  7 , 7 , 7 , 8 , 8 , 8 , 8 , 8 , 8 , 8 |  7.7 |  7.7 |
==============+======+==============================================+======+======+========
              |      |第一页 25,  2 , 3 , 2 , 21, 16, 9 , 20, 9 , 9 |  1.6 |      |
              |  一  +----------------------------------------------+------+  7.5 |
20000条记录时 |      |其它页  6 , 6 , 2 , 2 , 4 , 4 , 4 , 1 , 2 , 2 |  3.3 |      | 6.6533
              +------+----------------------------------------------+------+------+
              |  二  |每一页 54, 50, 37, 46, 49, 47, 52, 50, 55, 59 | 49.9 | 49.9 |
==============+======+==============================================+======+======+========
              |      |第一页 34, 35, 24, 21, 21, 21, 22, 22, 21, 21 | 25.2 |      |
              |  一  +----------------------------------------------+------+ 25.95|
30000条记录时 |      |其它页 14, 27, 40, 39, 37, 33, 22, 30, 14, 11 | 26.7 |      | 3.3372
              +------+----------------------------------------------+------+------+
              |  二  |每一页 92, 90, 83, 78, 93, 83, 91, 79, 89, 88 | 86.6 | 86.6 |
==============+======+==============================================+======+======+========