오라클 테이블 락 ( Table lock )

### Lock 확인 쿼리
SELECT do.object_name, do.owner, do.object_type,do.owner, vo.xidusn, vo.session_id,
vo.locked_mode
FROM v$locked_object vo , dba_objects do
WHERE vo.object_id = do.object_id ;

####  어떤 object에 어떤 lock이 걸렸는지 확인
SELECT  T1.object_name, DECODE(locked_mode, 2, 'ROW SHARE', 3, 'ROW EXCLUSIVE',  4, 'SHARE', 5, 'SHARE ROW EXCLUSIVE', 6, 'EXCLUSIVE', 'UNKNOWN') lock_mode
FROM  dba_objects T1, v$locked_object T2
WHERE T1.object_id = T2.object_id;

#### session 확인
select * from v$session where status = 'ACTIVE'

#### cursor 확인
v$open_cursor

#### 테이블의 lock 확인
SELECT A.SID, A.SERIAL#, B.TYPE, C.OBJECT_NAME
FROM V$SESSION A, V$LOCK B, DBA_OBJECTS C
WHERE A.SID=B.SID
AND B.ID1=C.OBJECT_ID
AND B.TYPE='TM'
AND C.OBJECT_NAME IN ('<테이블이름>');

/*******************************************************************************
* LOCK 관련
*******************************************************************************/
--V$LOCK 을 사용한 잠금 경합 모니터링
SELECT s.username, s.sid, s.serial#, s.logon_time,
  DECODE(l.type, 'TM', 'TABLE LOCK',
         'TX', 'ROW LOCK',
      NULL) "LOCK LEVEL",
  o.owner, o.object_name, o.object_type
FROM v$session s, v$lock l, dba_objects o
WHERE s.sid = l.sid
AND o.object_id = l.id1
AND s.username IS NOT NULL   

--락이 걸린 세션 자세히 알아보기
select a.sid, a.serial#,a.username,a.process,b.object_name,
decode(c.lmode,2,'RS',3,'RX',4,'S',5,'SRX',8,'X','NO') "TABLE LOCK",
decode (a.command,2,'INSERT',3,'SELECT',6,'UPDATE',7,'DELETE',12,'DROP TABLE',26,'LOCK TABLE','UNknown') "SQL",
decode(a.lockwait, NULL,'NO wait','Wait') "STATUS"
from v$session a,dba_objects b, v$lock c
where a.sid=c.sid and b.object_id=c.id1
and c.type='TM'

--락이 걸린 세션 간단히 알아보기
select a.sid, a.serial#, b.type, c.object_name, a.program, a.lockwait,
      a.logon_time, a.process, a.osuser, a.terminal
from v$session a, v$lock b, dba_objects c
where a.sid = b.sid
  and b.id1 = c.object_id
  and b.type = 'TM';

select a.sid, a.serial#, a.username, a.process, b.object_name
from v$session a , dba_objects b, v$lock c
where a.sid=c.sid and b.object_id = c.id1
and c.type = 'TM'

--락이 걸린 세션을 찾아 내어 세션을 죽이려고 해도 죽지 않는 경우
--아래 쿼리문으로 OS단의 PROCESS ID를 찾아내어 OS에서 죽인다
--kill -9 프로세스아이디
select substr(s.username,1,11) "ORACLE USER", p.pid "PROCESS ID",
s.sid "SESSION ID", s.serial#, osuser "OS USER",
p.spid "PROC SPID",s.process "SESS SPID", s.lockwait "LOCK WAIT"
from v$process p, v$session s, v$access a
where a.sid=s.sid and
p.addr=s.paddr and
s.username != 'SYS'

--위 쿼리문의 결과가 있다면 락이 걸린 세션이 있다는것이므로 아래의 쿼리문으로 세션을 죽인다
ALTER SYSTEM KILL SESSION '11,39061'

/**************************************************************************************/

출처 : http://cocoroworld.com/blog/root/entry/오라클-락lock