示例：Oracle表锁、行锁模拟和处理

for update模拟锁表

--session 1
SQL> select * from tt for update;

--session 2
SQL> update tt set id=1 where id=2;

按用户查询锁的情况

set line 300
col OBJECT_NAME format a30
col event format a30
col type format a10
col object_name format a15
col object_type format a15
SELECT l.sid, s.blocking_session blocker, s.event, l.type, l.lmode, l.request, o.object_name, o.object_type
FROM v$lock l, dba_objects o, v$session s
WHERE UPPER(s.username) = UPPER('&User')
AND   l.id1        = o.object_id (+)
AND   l.sid        = s.sid
ORDER BY sid, type;
Enter value for user: zylong
old   3: WHERE UPPER(s.username) = UPPER('&User')
new   3: WHERE UPPER(s.username) = UPPER('zylong')

       SID    BLOCKER EVENT                          TYPE            LMODE    REQUEST OBJECT_NAME     OBJECT_TYPE
---------- ---------- ------------------------------ ---------- ---------- ---------- --------------- ---------------
        27            SQL*Net message from client    AE                  4          0 ORA$BASE        EDITION
        32            SQL*Net message from client    AE                  4          0 ORA$BASE        EDITION
        35            SQL*Net message from client    AE                  4          0 ORA$BASE        EDITION
        35            SQL*Net message from client    TM                  3          0 TT              TABLE
        35            SQL*Net message from client    TX                  6          0
        40         35 enq: TX - row lock contention  AE                  4          0 ORA$BASE        EDITION
        40         35 enq: TX - row lock contention  TM                  3          0 TT              TABLE
        40         35 enq: TX - row lock contention  TX                  0          6

8 rows selected.

查询锁的源头

with lk as (select blocking_instance||'.'||blocking_session blocker, inst_id||'.'||sid waiter
       from gv$session
              where blocking_instance is not null
              and blocking_session is not null)
select lpad('  ',2*(level-1))||waiter lock_tree from
 (select * from lk
  union all
  select distinct 'root', blocker from lk
  where blocker not in (select waiter from lk))
connect by prior waiter=blocker start with blocker='root'; 

LOCK_TREE
--------------------------------------------------------------------------------------------------
1.35
  1.40

查询进程信息

col SPID for a10
col MACHINE for a15
col PROGRAM for a25
col OBJECT_NAME for a15
col ORACLE_USERNAME for a15
col OS_USER_NAME for a15
select b.session_id,
       a.serial#,
       p.spid,
       a.machine,
       a.program,
       a.status,
       c.object_name,
       b.oracle_username,
       b.os_user_name,
       a.sql_id
  from v$process p, v$session a, v$locked_object b, all_objects c
 where p.addr = a.paddr
   and a.process = b.process
   and c.object_id = b.object_id;

SESSION_ID    SERIAL# SPID       MACHINE         PROGRAM                   STATUS   OBJECT_NAME     ORACLE_USERNAME OS_USER_NAME    SQL_ID
---------- ---------- ---------- --------------- ------------------------- -------- --------------- --------------- --------------- -------------
        40       2237 13530      test            sqlplus@test (TNS V1-V3)  ACTIVE   TT              ZYLONG          oracle          1t3admr0mnxd6
        35       1675 13248      test            sqlplus@test (TNS V1-V3)  INACTIVE TT              ZYLONG          oracle

查询SQL信息

SQL> select SQL_TEXT from v$sql where SQL_ID='1t3admr0mnxd6'; 

SQL_TEXT
------------------------------------------------------------------------
update tt set id=1 where id=2

--or
set long 500000
select SQL_FULLTEXT from v$sql where SQL_ID='1t3admr0mnxd6';

kill session

alter system kill session '35,1675' immediate;

--or
$ ps -ef |grep spid
% kill -9 spid
c:\> orakill <SID> <spid>
其中<SID> = Oracle实例名称(ORACLE_SID) <spid> =要杀死的线程的线程ID