--以下几个为相关表

SELECT FROM v$lock;

SELECT FROM v$sqlarea;SELECT FROM v$session;

SELECT FROM v$process ;SELECT FROM v$locked_object;

SELECT FROM all_objects;SELECT * FROM v$session_wait;

--查看被锁的表

select b.owner,b.object_name,a.session_id,a.locked_mode from v$locked_object a,dba_objects b where b.object_id = a.object_id;

--查看那个用户那个进程照成死锁

select b.username,b.sid,b.serial#,logon_time from v$locked_object a,v$session b where a.session_id = b.sid order by b.logon_time;

--查看连接的进程

SELECT sid, serial#, username, osuser FROM v$session;

--3.查出锁定表的sid, serial#,os_user_name, machine_name, terminal，锁的type,mode

SELECT s.sid, s.serial#, s.username, s.schemaname, s.osuser, s.process, s.machine,s.terminal, s.logon_time, l.typeFROM v$session s, v$lock lWHERE s.sid = l.sidAND s.username IS NOT NULLORDER BY sid;

这个语句将查找到数据库中所有的DML语句产生的锁，还可以发现，

任何DML语句其实产生了两个锁，一个是表锁，一个是行锁。

--杀掉进程 sid,serial#

alter system kill session'210,11562';

查询指定用户状态：

select username,password,account_status,lock_date,profile from dba_users where username='NCCW';

解锁用户

SQL> alter user NCCW account unlock;

1. ORACLE中查看当前系统中锁表情况
   select * from v$locked_object
   可以通过查询v$locked_object拿到sid和objectid，然后用sid和v$session链表查询是哪里锁的表，用v$session中的objectid字段和dba_objects的id字段关联，查询详细的锁表情况。

查询SQL如下：

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, v$process p where ao.object_id = lo.object_id and lo.session_id = sess.sid;

查询是什么SQL引起了锁表的原因，SQL如下：

select l.session_id sid, s.serial#, l.locked_mode, l.oracle_username, s.user#, l.os_user_name, s.machine, s.terminal, a.sql_text, a.action from v$sqlarea a, v$session s, v$locked_object l where l.session_id = s.sid and s.prev_sql_addr = a.address order by sid, s.serial#;

2. ORACLE解锁的方法
   alter system kill session ’146′; –146为锁住的进程号，即spid

转自

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