查看PostgreSQL正在执行的SQL

SELECT
    procpid,
    START,
    now() - START AS lap,
    current_query
FROM
    (
        SELECT
            backendid,
            pg_stat_get_backend_pid (S.backendid) AS procpid,
            pg_stat_get_backend_activity_start (S.backendid) AS START,
            pg_stat_get_backend_activity (S.backendid) AS current_query
        FROM
            (
                SELECT
                    pg_stat_get_backend_idset () AS backendid
            ) AS S
    ) AS S
WHERE
    current_query <> '<IDLE>'
ORDER BY
    lap DESC;

procpid：进程id
start：进程开始时间
lap：经过时间
current_query：执行中的sql
怎样停止正在执行的sql
系统函数  kill -9 进程id

杀死进程  https://www.cnblogs.com/yulinlewis/p/11863750.html 


当前活跃连接数  select count( * ) from pg_stat_activity where state not like '%idle';