什么操作可以解锁

 

解锁可以通过commit   or   rollback来解除。  
    如果你加的是EXCLUSIVE 锁，下一次是加不上了的

 

   1.查找系统中谁在锁表 （有很多种方法）：

    a）.查找进程号和序列号

       SELECT T2.USERNAME, T2.SID, T2.SERIAL#, T2.LOGON_TIME
      FROM V$LOCKED_OBJECT T1, V$SESSION T2
      WHERE T1.SESSION_ID = T2.SID
      ORDER BY T2.LOGON_TIME;

   b）.查找进程号和序列号

    set echo OFF rem 该脚本是用来检验系统中谁在锁表 
   column username format a13
   column object_name format a10
   column osuser format a10
   column MACHINE format a10
   column LockType format a10  
   select A.sid,b.serial#,
       decode(A.type,'MR','Media Recovery','RT','Redo Thread',
                  'UN','User Name','TX','Transaction','TM','DML','UL','PL/SQL User Lock', 'DX','Distributed Xaction',
                  'CF','Control File','IS','Instance State','FS','File Set', 'IR', 'Instance Recovery', 'ST',
                  'Disk Space Transaction','TS','Temp Segment','IV','Library Cache Invalida-tion',
                  'LS','Log Start or Switch','RW','Row Wait','SQ', 'Sequence Number', 'TE',
                  'Extend Table','TT','Temp Table','Unknown')

        LockType,c.object_name,
       ---b.username,  
       ---b.osuser,  
       decode(a.lmode, 0,'None',1,'Null',2,'Row-S',3,'Row-X',
                 4,'Share',
                 5,'S/Row-X',
                 6,'Exclusive','Unknown')

       LockMode,
       B.MACHINE,
       D.SPID
  from v$lock a, v$session b, all_objects c, V$PROCESS D
 where a.sid = b.sid
   and a.type in ('TM', 'TX')
   and c.object_id = a.id1
   and B.PADDR = D.ADDR
    ---order by username /
 b）.查找进程号和序列号

   SELECT T2.USERNAME, T2.SID, T2.SERIAL#, T2.LOGON_TIME
   FROM V$LOCKED_OBJECT T1, V$SESSION T2
  WHERE T1.SESSION_ID = T2.SID
  ORDER BY T2.LOGON_TIME;

c）。查找进程号和序列号(查询出所有被锁的会话)：

SELECT   sn.username, m.SID,sn.SERIAL#, m.TYPE,
         DECODE (m.lmode,
                 0, 'None',
                 1, 'Null',
                 2, 'Row Share',
                 3, 'Row Excl.',
                 4, 'Share',
                 5, 'S/Row Excl.',
                 6, 'Exclusive',
                 lmode, LTRIM (TO_CHAR (lmode, '990'))
                ) lmode,
         DECODE (m.request,
                 0, 'None',
                 1, 'Null',
                 2, 'Row Share',
                 3, 'Row Excl.',
                 4, 'Share',
                 5, 'S/Row Excl.',
                 6, 'Exclusive',
                 request, LTRIM (TO_CHAR (m.request, '990'))
                ) request,
         m.id1, m.id2
    FROM v$session sn, v$lock m
   WHERE (sn.SID = m.SID AND m.request != 0)         --存在锁请求，即被阻塞
      OR (    sn.SID = m.SID                         --不存在锁请求，但是锁定的对象被其他会话请求锁定
          AND m.request = 0
          AND lmode != 4
          AND (id1, id2) IN (
                        SELECT s.id1, s.id2
                          FROM v$lock s
                         WHERE request != 0 AND s.id1 = m.id1
                               AND s.id2 = m.id2)
         )
ORDER BY id1, id2, m.request;

 

 2.杀进程(解锁):

    通过以上查询知道了sid和 SERIAL#（即：进程号,序列号）就可以开杀了
    ALTER SYSTEM KILL SESSION ‘SID,SERIR#’;