alter system kill session '436,35123';

7.RAC环境中锁查找

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

8.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;

9.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;

10.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;

11.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_id
GROUP BY o.OWNER,a.event
ORDER BY total_wait_time DESC;

SELECT   a.session_id,s.osuser,s.machine,s.program,o.owner,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.SID
GROUP BY o.owner,a.session_id,s.osuser
ORDER BY total_wait_time DESC;

12.查询当前连接会话数

select s.value,s.sid,a.username
from 
v$sesstat S,v$statname N,v$session A
where 
n.statistic#=s.statistic# and
name='session pga memory'
and s.sid=a.sid
order by s.value;

13.等待最多的用户

SELECT   s.SID,s.username,v$session s
   WHERE a.sample_time BETWEEN SYSDATE - 30 / 2880 AND SYSDATE
GROUP BY s.SID,s.username
ORDER BY total_wait_time DESC;

SELECT   a.program,a.user_id,d.username,s.sql_text,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_id
GROUP BY a.program,d.username;

SELECT hash_value,executions,buffer_gets,disk_reads,parse_calls
FROM V$sqlAREA
WHERE buffer_gets > 10000000 OR disk_reads > 1000000
ORDER BY buffer_gets + 100 * disk_reads DESC;

SELECT hash_value,parse_calls
FROM V$sqlAREA
WHERE hash_Value = 228801498 AND address = hextoraw('CBD8E4B0');

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,s.piece;

SELECT * FROM DBA_WAITERS;