数据库管理 Oracle锁处理、解锁相关方法和知识介绍

select sid,serial#,event,BLOCKING_SESSION from v$session where event like ‘%TX%’;

select sid,serial#,username,machine,blocking_session from v$session where sid=<SID>;

ALTER SYSTEM DISCONNECT SESSION ‘<SID>,<SERIAL>’ IMMEDIATE;

ALTER SYSTEM KILL SESSION ‘<SID>,<SERIAL>’;

col waiting_session for a20
col lock_type for a15
col mode_requested for a10
col mode_held for a10
col lock_id1 for a10
col lock_id2 for a10
set linesize 120
set pagesize 999
with dba_locks_cust as
(SELECT inst_id||’_’||sid session_id,
DECODE (TYPE,
‘MR’, ‘Media Recovery’,
‘RT’, ‘Redo Thread’,
‘UN’, ‘User Name’,
‘TX’, ‘Transaction’,
‘TM’, ‘DML’,
‘UL’, ‘PL/SQL User Lock’,
‘DX’, ‘Distributed Xaction’,
‘CF’, ‘Control File’,
‘IS’, ‘Instance State’,
‘FS’, ‘File Set’,
‘IR’, ‘Instance Recovery’,
‘ST’, ‘Disk Space Transaction’,
‘TS’, ‘Temp Segment’,
‘IV’, ‘Library Cache Invalidation’,
‘LS’, ‘Log Start or Switch’,
‘RW’, ‘Row Wait’,
‘SQ’, ‘Sequence Number’,
‘TE’, ‘Extend Table’,
‘TT’, ‘Temp Table’,
TYPE)
lock_type,
DECODE (lmode,
0, ‘None’, /* Mon Lock equivalent */
1, ‘Null’, /* N */
2, ‘Row-S (SS)’, /* L */
3, ‘Row-X (SX)’, /* R */
4, ‘Share’, /* S */
5, ‘S/Row-X (SSX)’, /* C */
6, ‘Exclusive’, /* X */
TO_CHAR (lmode))
mode_held,
DECODE (request,
0, ‘None’, /* Mon Lock equivalent */
1, ‘Null’, /* N */
2, ‘Row-S (SS)’, /* L */
3, ‘Row-X (SX)’, /* R */
4, ‘Share’, /* S */
5, ‘S/Row-X (SSX)’, /* C */
6, ‘Exclusive’, /* X */
TO_CHAR (request))
mode_requested,
TO_CHAR (id1) lock_id1,
TO_CHAR (id2) lock_id2,
ctime last_convert,
DECODE (block,
0, ‘Not Blocking’, /* Not blocking any other processes */
1, ‘Blocking’, /* This lock blocks other processes */
2, ‘Global’, /* This lock is global, so we can’t tell */
TO_CHAR (block))
blocking_others
FROM gv$lock
),
lock_temp as
(select * from dba_locks_cust),
lock_holder as
(
select w.session_id waiting_session,
h.session_id holding_session,
w.lock_type,
h.mode_held,
w.mode_requested,
w.lock_id1,
w.lock_id2
from lock_temp w, lock_temp h
where h.blocking_others in (‘Blocking’,’Global’)
and h.mode_held != ‘None’
and h.mode_held != ‘Null’
and w.mode_requested != ‘None’
and w.lock_type = h.lock_type
and w.lock_id1 = h.lock_id1
and w.lock_id2 = h.lock_id2
),
lock_holders as
(select waiting_session,holding_session,lock_type,mode_held,
mode_requested,lock_id1,lock_id2
from lock_holder
union all
select holding_session, null, ‘None’, null, null, null, null
from lock_holder
minus
select waiting_session, null, ‘None’, null, null, null, null
from lock_holder
)
select lpad(‘ ‘,3*(level-1)) || waiting_session waiting_session,
lock_type,
mode_requested,
mode_held,
lock_id1,
lock_id2
from lock_holders
connect by prior waiting_session = holding_session
start with holding_session is null;