Postgresql锁表的问题

select * from pg_stat_activity WHERE datname='aaa' and wait_event_type = 'Lock'

aaa是数据库名称

select pg_cancel_backend('上面查到的pid');
select pg_cancel_backend('上面查到的pid');
select pg_cancel_backend('上面查到的pid');
select pg_cancel_backend('上面查到的pid');
select pg_cancel_backend('上面查到的pid');