在索引列上运行简单查询,但它需要超过500毫秒.这些查询经常运行,因此它会大大影响性能.
表中只有1M行,一个非常简单的表.使用MyISAM.我不明白为什么它会检查所有行,似乎它忽略了索引!我尝试在字段上添加第二个索引,一个普通索引而不是唯一索引,没有任何区别.谢谢你的期待.
# Time: 130730 22:00:07
# User@Host: engine[engine] @ engine [10.0.0.6]
# Query_time: 0.511209 Lock_time: 0.000050 Rows_sent: 1 Rows_examined: 932048
SET timestamp=1375236007;
SELECT * FROM `marketplacesales`.`sales_order` WHERE `marketplace_orderid` = 823123693003;
+---------------------+-----------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+---------------------+-----------------------+------+-----+---------+----------------+
| id | mediumint(8) unsigned | NO | PRI | NULL | auto_increment |
| marketplace_id | smallint(5) unsigned | NO | MUL | NULL | |
| marketplace_orderid | varchar(255) | NO | …mysql ×1