Oracle数据库--表锁的情况查询

1.查找当前表级锁的SQL如下：

select sess.sid,     sess.serial#,     lo.oracle_username,     lo.os_user_name,     ao.object_name,     lo.locked_mode     from v$locked_object lo,     dba_objects ao,     v$session sess where ao.object_id = lo.object_id and lo.session_id = sess.sid;

2.杀掉锁表进程：

alter system kill session '436,35123';

3.RAC环境中锁查找：

SELECT inst_id,DECODE(request,0,'Holder: ','Waiter: ')||sid sess,         id1, id2, lmode, request, type,block,ctimeFROM GV$LOCKWHERE (id1, id2, type) IN       (SELECT id1, id2, type FROM GV$LOCK WHERE request>0)ORDER BY id1, request;

4.监控当前数据库谁在运行什么SQL语句

select osuser, username, sql_text  from  v$session a, v$sqltext b where  a.sql_address =b.address order by address, piece;

5.找使用CPU多的用户session

select a.sid,spid,status,substr(a.program,1,40) prog, a.terminal,osuser,value/60/100 value from  v$session a,v$process b,v$sesstat c where  c.statistic#=12 and         c.sid=a.sid and         a.paddr=b.addr         order by value desc;

6.查看死锁信息

SELECT (SELECT username          FROM v$session         WHERE SID = a.SID) blocker, a.SID, 'is blocking',       (SELECT username          FROM v$session         WHERE SID = b.SID) blockee, b.SID  FROM v$lock a, v$lock b WHERE a.BLOCK = 1 AND b.request > 0 AND a.id1 = b.id1 AND a.id2 = b.id2;

7.具有最高等待的对象

SELECT   o.OWNER,o.object_name, o.object_type, a.event,         SUM (a.wait_time + a.time_waited) total_wait_time    FROM v$active_session_history a, dba_objects o   WHERE a.sample_time BETWEEN SYSDATE - 30 / 2880 AND SYSDATE     AND a.current_obj# = o.object_idGROUP BY o.OWNER,o.object_name, o.object_type, a.eventORDER BY total_wait_time DESC;SELECT   a.session_id, s.osuser, s.machine, s.program, o.owner, o.object_name,         o.object_type, a.event,         SUM (a.wait_time + a.time_waited) total_wait_time    FROM v$active_session_history a, dba_objects o, v$session s   WHERE a.sample_time BETWEEN SYSDATE - 30 / 2880 AND SYSDATE     AND a.current_obj# = o.object_id     AND a.session_id = s.SIDGROUP BY o.owner,         o.object_name,         o.object_type,         a.event,         a.session_id,         s.program,         s.machine,         s.osuserORDER BY total_wait_time DESC;

8.查询当前连接会话数

select s.value,s.sid,a.usernamefrom v$sesstat S,v$statname N,v$session Awhere n.statistic#=s.statistic# andname='session pga memory'and s.sid=a.sidorder by s.value;

9.等待最多的用户

SELECT   s.SID, s.username, SUM (a.wait_time + a.time_waited) total_wait_time    FROM v$active_session_history a, v$session s   WHERE a.sample_time BETWEEN SYSDATE - 30 / 2880 AND SYSDATEGROUP BY s.SID, s.usernameORDER BY total_wait_time DESC;

10.等待最多的SQL

SELECT   a.program, a.session_id, a.user_id, d.username, s.sql_text,         SUM (a.wait_time + a.time_waited) total_wait_time    FROM v$active_session_history a, v$sqlarea s, dba_users d   WHERE a.sample_time BETWEEN SYSDATE - 30 / 2880 AND SYSDATE     AND a.sql_id = s.sql_id     AND a.user_id = d.user_idGROUP BY a.program, a.session_id, a.user_id, s.sql_text, d.username;

11.查看消耗资源最多的SQL

SELECT hash_value, executions, buffer_gets, disk_reads, parse_callsFROM V$SQLAREAWHERE buffer_gets > 10000000 OR disk_reads > 1000000ORDER BY buffer_gets + 100 * disk_reads DESC;

12.查看某条SQL语句的资源消耗

SELECT hash_value, buffer_gets, disk_reads, executions, parse_callsFROM V$SQLAREAWHERE hash_Value = 228801498 AND address = hextoraw('CBD8E4B0');

13.查询会话执行的实际SQL

SELECT   a.SID, a.username, s.sql_text    FROM v$session a, v$sqltext s   WHERE a.sql_address = s.address     AND a.sql_hash_value = s.hash_value     AND a.status = 'ACTIVE'ORDER BY a.username, a.SID, s.piece;

14.显示正在等待锁的所有会话

SELECT * FROM DBA_WAITERS;