查询链接数

SELECT sum(numbackends) FROM pg_stat_database;

查看死锁状态

select pid,
       usename,
       pg_blocking_pids(pid) as blocked_by,
       query as blocked_query
from pg_stat_activity
where cardinality(pg_blocking_pids(pid)) > 0;

删除死锁进程

SELECT pg_cancel_backend(__pid__);

SELECT pg_terminate_backend(__pid__);