无详细内容 Oracle Oracle的锁表与解锁 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.osuserFROM v$session s,
<无详细内容> Oracle $velocityCount-->Oracle的锁表与解锁 SELECT /*+ rule */ s.username, decode(l.type,'TM','TABLE LOCK', 'TX','ROW LOCK', NULL) LOCK_LEVEL, o.owner,o.object_name,o.object_type, s.sid,s.serial#,s.terminal,s.machine,s.program,s.osuser FROM v$session s,v$lock l,dba_objects o WHERE l.sid = s.sid AND l.id1 = o.object_id(+) AND s.username is NOT Null --kill session语句 alter system kill session'50,492'; --以下几个为相关表 SELECT * FROM v$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$session_wait; --1.查出锁定object的session的信息以及被锁定的object名 SELECT l.session_id sid, s.serial#, l.locked_mode,l.oracle_username, l.os_user_name,s.machine, s.terminal, o.object_name, s.logon_time FROM v$locked_object l, all_objects o, v$session s WHERE l.object_id = o.object_id AND l.session_id = s.sid ORDER BY sid, s.serial# ; --2.查出锁定表的session的sid, serial#,os_user_name, machine name, terminal和执行的语句 --比上面那段多出sql_text和action SELECT l.session_id sid, s.serial#, l.locked_mode, l.oracle_username, s.user#, l.os_user_name,s.machine, s.terminal,a.sql_text, a.action FROM v$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.查出锁定表的sid, serial#,os_user_name, machine_name, terminal,锁的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; 这个语句将查找到数据库中所有的DML语句产生的锁,还可以发现, 任何DML语句其实产生了两个锁,一个是表锁,一个是行锁。 杀锁命令 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 如果发生了锁等待,我们可能更想知道是谁锁了表而引起谁的等待 以下的语句可以查询到谁锁了表,而谁在等待。 以上查询结果是一个树状结构,如果有子节点,则表示有等待发生。 如果想知道锁用了哪个回滚段,还可以关联到V$rollname,其中xidusn就是回滚段的USN col user_name format a10 col owner format a10 col object_name format a10 col object_type format a10 SELECT /*+ rule */ lpad(' ',decode(l.xidusn ,0,3,0))||l.oracle_username User_name, o.owner,o.object_name,o.object_type,s.sid,s.serial# FROM v$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