oracle的鎖表與解鎖
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語句
alter system kill session'50,492';
--以下幾個為相關表
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的資訊以及被鎖定的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和執行的語句
--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$lock l
where s.sid = l.sid
and s.username is not null
order by sid;
這個語句將查詢到資料庫中所有的dml語句產生的鎖，還可以發現，
任何dml語句其實產生了兩個鎖，乙個是表鎖，乙個是行鎖。
殺鎖命令
alter system kill session 'sid,serial#'
select /*+ rule */ s.username,
decode(l.type,'tm','table lock',
'tx','row lock',
null) lock_level,
o.owner,o.object_name,o.object_type,
s.sid,s.serial#,s.terminal,s.machine,s.program,s.osuser
from v$session s,v$lock l,dba_objects o
where l.sid = s.sid
and l.id1 = o.object_id(+)
and s.username is not null
如果發生了鎖等待，我們可能更想知道是誰鎖了表而引起誰的等待
以下的語句可以查詢到誰鎖了表，而誰在等待。
以上查詢結果是乙個樹狀結構，如果有子節點，則表示有等待發生。
如果想知道鎖用了哪個回滾段，還可以關聯到v$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
Oracle的鎖表與解鎖
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...
Oracle的鎖表與解鎖
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...
Oracle的鎖表與解鎖
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...