PostgreSQL数据库锁查询及终止

问题场景：在测试计划任务时，发现启动时无反应，经分析是因为开发都公用一个Pg数据库，基于计划任务会有数据库锁抢占的情况，如果有人调度计划任务打断点卡住的话就很容易出现死锁。

解决方法：查询出死锁的进程ID（blocking_pid），手工终止，查询及处理SQL如下。

--查询锁
SELECT blocked_locks.pid     AS blocked_pid,
	blocked_activity.usename  AS blocked_user,
	blocking_locks.pid     AS blocking_pid,
	blocking_activity.usename AS blocking_user,
	blocked_activity.query    AS blocked_statement,
	blocking_activity.query   AS current_statement_in_blocking_process
FROM  pg_catalog.pg_locks         blocked_locks
JOIN pg_catalog.pg_stat_activity blocked_activity  ON blocked_activity.pid = blocked_locks.pid
JOIN pg_catalog.pg_locks         blocking_locks
	ON blocking_locks.locktype = blocked_locks.locktype
	AND blocking_locks.DATABASE IS NOT DISTINCT FROM blocked_locks.DATABASE
	AND blocking_locks.relation IS NOT DISTINCT FROM blocked_locks.relation
	AND blocking_locks.page IS NOT DISTINCT FROM blocked_locks.page
	AND blocking_locks.tuple IS NOT DISTINCT FROM blocked_locks.tuple
	AND blocking_locks.virtualxid IS NOT DISTINCT FROM blocked_locks.virtualxid
	AND blocking_locks.transactionid IS NOT DISTINCT FROM blocked_locks.transactionid
	AND blocking_locks.classid IS NOT DISTINCT FROM blocked_locks.classid
	AND blocking_locks.objid IS NOT DISTINCT FROM blocked_locks.objid
	AND blocking_locks.objsubid IS NOT DISTINCT FROM blocked_locks.objsubid
	AND blocking_locks.pid != blocked_locks.pid
JOIN pg_catalog.pg_stat_activity blocking_activity ON blocking_activity.pid = blocking_locks.pid
WHERE NOT blocked_locks.GRANTED;

--终止锁
select pg_terminate_backend(19964);