MySQL 查询优化器

启用 optimizer_trace 功能来获取更详细的查询优化过程信息

SET optimizer_trace="enabled=on";

执行查询

select *
from student;

查询 information_schema.optimizer_trace 表获取详细的优化器跟踪信息

select * from information_schema.optimizer_trace;

禁用 optimizer_trace

SET optimizer_trace="enabled=off";