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1.下面的語(yǔ)句用來(lái)查詢哪些對(duì)象被鎖:
select object_name,machine,s.sid,s.serial#
from v$locked_object l,dba_objects o ,v$session s
where l.object_id = o.object_id and l.session_id=s.sid;
2.下面的語(yǔ)句用來(lái)殺死一個(gè)進(jìn)程:
alter system kill session '24,111'; (其中24,111分別是上面查詢出的sid,serial#)
【注】以上兩步,可以通過(guò)Oracle的管理控制臺(tái)來(lái)執(zhí)行。
3.如果利用上面的命令殺死一個(gè)進(jìn)程后,進(jìn)程狀態(tài)被置為"killed",但是鎖定的資源很長(zhǎng)時(shí)間沒(méi)有被釋放,那么可以在os一級(jí)再殺死相應(yīng)的進(jìn)程(線程),首先執(zhí)行下面的語(yǔ)句獲得進(jìn)程(線程)號(hào):
select spid, osuser, s.program
from v$session s,v$process p
where s.paddr=p.addr and s.sid=24 (24是上面的sid)
4.在OS上殺死這個(gè)進(jìn)程(線程):
1)在unix上,用root身份執(zhí)行命令:
#kill -9 12345(即第3步查詢出的spid)
2)在windows(unix也適用)用orakill殺死線程,orakill是oracle提供的一個(gè)可執(zhí)行命令,語(yǔ)法為:
orakill sid thread
其中:
sid:表示要?dú)⑺赖倪M(jìn)程屬于的實(shí)例名
thread:是要?dú)⒌舻木程號(hào),即第3步查詢出的spid。
例:c:>orakill orcl 12345
SELECT /*+ rule */ s.username,
decode(l.type,'TM','TABLE LOCK',
'TX','ROW LOCK',
NULL) LOCK_LEVEL,
o.owner,o.object_name,o.object_type,
s.sid,s.serial#,s.terminal,s.machine,s.program,s.osuser
FROM v$session s,v$lock l,dba_objects o
WHERE l.sid = s.sid
AND l.id1 = o.object_id(+)
AND s.username is NOT Null
--kill session語(yǔ)句
alter system kill session'50,492';
--以下幾個(gè)為相關(guān)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;
--1.查出鎖定object的session的信息以及被鎖定的object名
SELECT l.session_id sid, s.serial#, l.locked_mode,l.oracle_username,
l.os_user_name,s.machine, s.terminal, o.object_name, s.logon_time
FROM v$locked_object l, all_objects o, v$session s
WHERE l.object_id = o.object_id
AND l.session_id = s.sid
ORDER BY sid, s.serial# ;
--2.查出鎖定表的session的sid, serial#,os_user_name, machine name, terminal和執(zhí)行的語(yǔ)句
--比上面那段多出sql_text和action
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$locked_object l
WHERE l.session_id = s.sid
AND s.prev_sql_addr = a.address
ORDER BY sid, s.serial#;
--3.查出鎖定表的sid, serial#,os_user_name, machine_name, terminal,鎖的type,mode
SELECT s.sid, s.serial#, s.username, s.schemaname, s.osuser, s.process, s.machine,
s.terminal, s.logon_time, l.type
FROM v$session s, v$lock l
WHERE s.sid = l.sid
AND s.username IS NOT NULL
ORDER BY sid;
這個(gè)語(yǔ)句將查找到數(shù)據(jù)庫(kù)中所有的DML語(yǔ)句產(chǎn)生的鎖,還可以發(fā)現(xiàn),
任何DML語(yǔ)句其實(shí)產(chǎn)生了兩個(gè)鎖,一個(gè)是表鎖,一個(gè)是行鎖。
殺鎖命令
alter system kill session 'sid,serial#'
SELECT /*+ rule */ s.username,
decode(l.type,'TM','TABLE LOCK',
'TX','ROW LOCK',
NULL) LOCK_LEVEL,
o.owner,o.object_name,o.object_type,
s.sid,s.serial#,s.terminal,s.machine,s.program,s.osuser
FROM v$session s,v$lock l,dba_objects o
WHERE l.sid = s.sid
AND l.id1 = o.object_id(+)
AND s.username is NOT NULL
如果發(fā)生了鎖等待,我們可能更想知道是誰(shuí)鎖了表而引起誰(shuí)的等待
以下的語(yǔ)句可以查詢到誰(shuí)鎖了表,而誰(shuí)在等待。
以上查詢結(jié)果是一個(gè)樹(shù)狀結(jié)構(gòu),如果有子節(jié)點(diǎn),則表示有等待發(fā)生。
如果想知道鎖用了哪個(gè)回滾段,還可以關(guān)聯(lián)到V$rollname,其中xidusn就是回滾段的USN
col user_name format a10
col owner format a10
col object_name format a10
col object_type format a10
SELECT /*+ rule */ lpad(' ',decode(l.xidusn ,0,3,0))||l.oracle_username User_name,
o.owner,o.object_name,o.object_type,s.sid,s.serial#
FROM v$locked_object l,dba_objects o,v$session s
WHERE l.object_id=o.object_id
AND l.session_id=s.sid
ORDER BY o.object_id,xidusn DESC |
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