mysql> explain select * from dg_users order by uid desc limit 83,10; +----+-------------+----------+------+---------------+------+---------+------+------+----------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+----------+------+---------------+------+---------+------+------+----------------+ | 1 | SIMPLE | dg_users | ALL | NULL | NULL | NULL | NULL | 2319 | Using filesort | +----+-------------+----------+------+---------------+------+---------+------+------+----------------+ 1 row in set (0.00 sec) mysql> explain select * from dg_users order by uid desc limit 82,10; +----+-------------+----------+-------+---------------+---------+---------+------+------+-------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+----------+-------+---------------+---------+---------+------+------+-------+ | 1 | SIMPLE | dg_users | index | NULL | PRIMARY | 4 | NULL | 92 | NULL | +----+-------------+----------+-------+---------------+---------+---------+------+------+-------+ 1 row in set (0.00 sec)
这就像结果。 当我改变＆＃34;限制82,10＆＃34;为了限制83,10＆＃34;，钥匙将丢失。
我只是想知道为什么？认为