Oracle阻塞(blockingblocked)实例详解

--更新表，注，提示符scott@CNMMBO表明用户为scott的session，用户名不同，session不同。scott@CNMMBO> update emp set sal=sal*1.1 where empno=7788;1 row updated.scott@CNMMBO> @my_env SPID        SID  SERIAL# USERNAME    PROGRAM------------ ---------- ---------- --------------- ------------------------------------------------11205       1073    4642 robin      oracle@SZDB (TNS V1-V3) --另起两个session更新同样的行，这两个session都会处于等待，直到第一个session提交或回滚leshami@CNMMBO> update scott.emp set sal=sal+100 where empno=7788; goex_admin@CNMMBO> update scott.emp set sal=sal-50 where empno=7788; --下面在第一个session 查询阻塞情况scott@CNMMBO> @blocker  BLOCK_MSG                        BLOCK-------------------------------------------------- ----------pts/5 ('1073,4642') is blocking 1067,10438         1pts/5 ('1073,4642') is blocking 1065,4464          1--上面的结果表明session 1073,4642 阻塞了后面的2个--即session 1073,4642是阻塞者，后面2个session是被阻塞者 --Author : Leshami--Blog  : http://blog.csdn.net/leshami --下面查询正在阻塞的session id，SQL语句以及被阻塞的时间scott@CNMMBO> @blocking_session_detail.sql 'SID='||A.SID||'WAITCLASS='||A.WAIT_CLASS||'TIME='||A.SECONDS_IN_WAIT||CHR(10)||'QUERY='||B.SQL_TEXT------------------------------------------------------------------------sid=1067 Wait Class=Application Time=5995 Query=update scott.emp set sal=sal+100 where empno=7788 sid=1065 Wait Class=Application Time=225 Query=update scott.emp set sal=sal-50 where empno=7788 --下面的查询阻塞时锁的持有情况 scott@CNMMBO> @request_lock_type USERNAME               SID TY LMODE    REQUEST      ID1    ID2------------------------------ ---------- -- ----------- ----------- ---------- ----------SCOTT                1073 TX Exclusive  None      524319   27412LESHAMI               1067 TX None    Exclusive    524319   27412GOEX_ADMIN              1065 TX None    Exclusive    524319   27412--可以看到LESHAMI，GOEX_ADMIN 2个用户都在请求524319/27412上的Exclusive锁，而此时已经被SCOTT加了Exclusive锁 --查询阻塞时锁的持有详细信息scott@CNMMBO> @request_lock_detail     SID USERNAME       OSUSER     TERMINAL         OBJECT_NAME     TY Lock Mode  Req_Mode---------- -------------------- --------------- ------------------------- -------------------- -- ----------- --------------------   1065 GOEX_ADMIN      robin      pts/1           EMP         TM Row Excl   1065 GOEX_ADMIN      robin      pts/1           Trans-524319     TX --Waiting-- Exclusive   1067 LESHAMI       robin      pts/0           EMP         TM Row Excl   1067 LESHAMI       robin      pts/0           Trans-524319     TX --Waiting-- Exclusive   1073 SCOTT        robin      pts/5           EMP         TM Row Excl   1073 SCOTT        robin      pts/5           Trans-524319     TX Exclusive 

robin@SZDB:~/dba_scripts/custom/sql> more my_env.sql SELECT spid, s.sid, s.serial#, p.username, p.programFROM v$process p, v$session sWHERE p.addr = s.paddr   AND s.sid = (SELECT sid          FROM v$mystat          WHERE rownum = 1);robin@SZDB:~/dba_scripts/custom/sql> more blocker.sql col block_msg format a50; select c.terminal||' ('''||a.sid||','||c.serial#||''') is blocking '||b.sid||','||d.serial# block_msg, a.block from v$lock a,v$lock b,v$session c,v$session d  where a.id1=b.id1  and a.id2=b.id2  and a.block>0 and a.sid <>b.sid  and a.sid=c.sid  and b.sid=d.SID; robin@SZDB:~/dba_scripts/custom/sql> more blocking_session_detail.sql--To find the query for blocking session--Access Privileges: SELECT on v$session, v$sqlareaSELECT   'sid='     || a.SID     || ' Wait Class='     || a.wait_class     || ' Time='     || a.seconds_in_wait     || CHR (10)     || ' Query='     || b.sql_text  FROM v$session a, v$sqlarea b  WHERE a.blocking_session IS NOT NULL AND a.sql_address = b.addressORDER BY a.blocking_session/robin@SZDB:~/dba_scripts/custom/sql> more request_lock_type.sql--This script generates a report of users waiting for locks.--Access Privileges: SELECT on v$session, v$lockSELECT sn.username, m.sid, m.type,    DECODE(m.lmode, 0, 'None',            1, 'Null',            2, 'Row Share',            3, 'Row Excl.',            4, 'Share',            5, 'S/Row Excl.',            6, 'Exclusive',        lmode, ltrim(to_char(lmode,'990'))) lmode,    DECODE(m.request,0, 'None',             1, 'Null',             2, 'Row Share',             3, 'Row Excl.',             4, 'Share',             5, 'S/Row Excl.',             6, 'Exclusive',             request, ltrim(to_char(m.request,        '990'))) request, m.id1, m.id2FROM v$session sn, v$lock mWHERE (sn.sid = m.sid AND m.request != 0)    OR (sn.sid = m.sid        AND m.request = 0 AND lmode != 4        AND (id1, id2) IN (SELECT s.id1, s.id2   FROM v$lock s            WHERE request != 0       AND s.id1 = m.id1                AND s.id2 = m.id2)        )ORDER BY id1, id2, m.request; robin@SZDB:~/dba_scripts/custom/sql> more request_lock_detail.sqlset linesize 190col osuser format a15col username format a20 wrapcol object_name format a20 wrapcol terminal format a25 wrapcol Req_Mode format a20select B.SID, C.USERNAME, C.OSUSER, C.TERMINAL,    DECODE(B.ID2, 0, A.OBJECT_NAME,      'Trans-'||to_char(B.ID1)) OBJECT_NAME,   B.TYPE,    DECODE(B.LMODE,0,'--Waiting--',           1,'Null',           2,'Row Share',           3,'Row Excl',          4,'Share',           5,'Sha Row Exc',      6,'Exclusive',            'Other') "Lock Mode",    DECODE(B.REQUEST,0,' ',           1,'Null',           2,'Row Share',           3,'Row Excl',           4,'Share',           5,'Sha Row Exc',           6,'Exclusive',           'Other') "Req_Mode" from DBA_OBJECTS A, V$LOCK B, V$SESSION Cwhere A.OBJECT_ID(+) = B.ID1 and B.SID = C.SID and C.USERNAME is not nullorder by B.SID, B.ID2;