死锁

查看是否有死锁

select sess.sid,
       sess.serial#,
       lo.oracle_username,
       lo.os_user_name,
       ao.object_name,
       lo.locked_mode
  from v$locked_object lo, dba_objects ao, v$session sess
 where ao.object_id = lo.object_id
   and lo.session_id = sess.sid;

杀死进程 

alter system kill session 'sid,serial#';
--例如
alter system kill session '653,34420' immediate;

一下不好用

检查死锁的sql

select sql_text
  from v$sql
 where hash_value in
       (select sql_hash_value
          from v$session
         where sid in (select session_id from v$locked_object));

检查死锁用户的sql

select b.username, b.serial#, d.id1, a.sql_text
  from v$lock d, v$session b, v$sqltext a
 where b.lockwait = d.kaddr
   and a.address = b.sql_address
   and a.hash_value = b.sql_hash_value;

确定谁锁了谁

select s1.username || '@' || s1.machine || ' ( SID=' || s1.sid ||
       ' )  is blocking ' || s2.username || '@' || s2.machine || ' ( SID=' ||
       s2.sid || ' ) ' AS blocking_status
  from v$lock l1, v$session s1, v$lock l2, v$session s2
 where s1.sid = l1.sid
   and s2.sid = l2.sid
   and l1.BLOCK = 1
   and l2.request > 0
   and l1.id1 = l2.id1
   and l2.id2 = l2.id2;

确定链接的sql

select sql_text from v$session v,v$sql s where SID=345 and v.sql_hash_value = s.hash_value;

 https://blog.csdn.net/zjun007/article/details/86151912