用%20force%20index()指定想要走的索引

一、使用explain工具分析sql

explain%20select%20count(id)%20from%20person_info_large;

二、修改sql或者尽量让sql走索引 explain select count(id) from person_info_large force index (primary);

原文链接：https://blog.csdn.net/loulanyue_/article/details/104139853