当我在MysqL CLI(在运行相关PHP脚本的同一台计算机上)运行此查询时,需要0.10秒 – 即使抛出sql_NO_CACHE标志.

当我运行这个查询,准备通过PDO,它需要超过9秒.这只是执行() – 不包括获取调用所需的时间.

我的查询示例：

SELECT HEX(al.uuid) hexUUID,al.created_on,IFNULL(al.state,'ON') actionTyPE,pp.publishers_id publisher_id,pp.PRoducts_id product_id,al.action_id,al.last_updated
From ActionAPI.actionLists al
LEFT JOIN ActionAPI.publishers_products pp
    ON al.publisher_product_id = pp.id
WHERE (al.test IS NULL OR al.test = 0)
    AND (al.created_on >= :since OR al.last_updated >= :since)
ORDER BY created_on ASC
LIMIT :skip,100;

我不认为查询是错误的,考虑到我尝试过的每一个本地MysqL客户端已经运行在几乎瞬间,但是这里是ExpLaiN for kicks：

+----+-------------+-------+--------+-------------------------+------------+---------+-----------------------------------+------+-------------+
| id | select_type | table | type   | possible_keys           | key        | key_len | ref                               | rows | Extra       |
+----+-------------+-------+--------+-------------------------+------------+---------+-----------------------------------+------+-------------+
|  1 | SIMPLE      | al    | index  | created_on,last_updated | created_on | 8       | NULL                              |  100 | Using where |
|  1 | SIMPLE      | pp    | eq_ref | Primary                 | PRIMARY    | 4       | ActionAPI.al.publisher_product_id |    1 |             |
+----+-------------+-------+--------+-------------------------+------------+---------+-----------------------------------+------+-------------+
2 rows in set (0.00 sec)

PDO在做什么在世界上花了8.9秒？

编辑：正如注释中所述,我已经编写了一个这样的MysqL_query版本,并且性能相同.然而,删除WHERE子句的一部分使其运行速度与MysqL客户端一样快.继续阅读令人难以置信的细节.