我有一个非常奇怪的问题与MySQL和简单的查询与简单的索引。我试图使用这个查询：

SELECT * FROM `counter_links` WHERE `link_id`=1544;正如你所看到的，还有一个名为link_id的索引：

mysql> show indexes from counter_links;

+---------------+------------+-------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+----------+---------------+

| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |

+---------------+------------+-------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+----------+---------------+

| counter_links | 1 | link_id | 1 | link_id | A | NULL | NULL | NULL | | BTREE | disabled | |

+---------------+------------+-------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+----------+---------------+

1 row in set (0.12 sec)但看看EXPLAIN返回的内容：

mysql> explain SELECT * FROM `counter_links` WHERE `link_id`=1544;

+----+-------------+---------------+------+---------------+------+---------+------+----------+-------------+

| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |

+----+-------------+---------------+------+---------------+------+---------+------+----------+-------------+

| 1 | SIMPLE | counter_links | ALL | NULL | NULL | NULL | NULL | 22103687 | Using where |

+----+-------------+---------------+------+---------------+------+---------+------+----------+-------------+

1 row in set (0.03 sec)为什么mySQL不在那里使用索引？我发现在较小版本的桌面上同样可行，但我无法识别问题出在哪里。你做？

看起来更奇怪，因为较低的ID有时适用于索引。

感谢您提前提出所有意见！

干杯!

的Jakub