minna_D的专栏

一、查看当前数据库连接SELECT pg_stat_get_backend_pid(s.backendid) AS procpid, pg_stat_get_backend_activity(s.backendid) AS current_query FROM (SELECT pg_stat_get_backend_idset() AS backendid) AS s;

博客主页：http://blog.youkuaiyun.com/minna_d1. 关于count及sumcount结果用不null,sum可能会出现null的情况hotel=> select count(0), count(1), count(*) , count(id), sum(1), sum(id) from info_op_log where id = -1; count