优化临时表使用SQL语句性能提升100倍

【问题现象】 线上mysql数据库爆出一个慢查询,DBA观察发现,查询时服务器IO飙升,IO占用率达到, 执行时间长达7s左右。 SQL语句如下: SELECT DISTINCT g.*, cp.name AS cp_name, c.name AS category_name, t.name AS type_name FROMgm_game g LEFT JOIN gm_cp cp ON cp.id = g.cp_id AND cp.deleted = 0 LEFT JOIN gm_category c ON c.id = g.category_id AND c.delete