摘要:
一、extra 二、extra实例 1、Using temporary 使用了临时表 EXPLAIN select * from myshop.ecs_users where user_id in ( select user_id from myshop.ecs_users where user_i 阅读全文
摘要:
mysql 执行计划 SET optimizer_trace = "enabled=on";sql 语句 select trace FROM information_scheme.optimizer_trace; SET optimizer_trace=“enable=off”; 执行完会返回一个j 阅读全文