解决oracle语句卡死

---正在执行的

select a.username, a.sid,b.SQL_TEXT, b.SQL_FULLTEXT
  from v$session a, v$sqlarea b 
where a.sql_address = b.address 
---执行过的
select b.SQL_TEXT,b.FIRST_LOAD_TIME,b.SQL_FULLTEXT
  from v$sqlarea b
where b.FIRST_LOAD_TIME between \'2009-10-15/09:24:47\' and
       \'2009-10-15/09:24:47\' order by b.FIRST_LOAD_TIME 
（此方法好处可以查看某一时间段执行过的sql，并且 SQL_FULLTEXT 包含了完整的 sql 语句）

其他
select OSUSER,PROGRAM,USERNAME,SCHEMANAME,B.Cpu_Time,STATUS,B.SQL_TEXT 
from V$SESSION A LEFT JOIN V$SQL B ON A.SQL_ADDRESS=B.ADDRESS AND A.SQL_HASH_VALUE=B.HASH_VALUE order by b.cpu_time desc 


select address, sql_text, piece 
  from v$session, v$sqltext 
where address = sql_address 
  -- and machine = < you machine name > 
order by address, piece 

查找前十条性能差的sql. 

SELECT * FROM (select PARSING_USER_ID,EXECUTIONS,SORTS, 
COMMAND_TYPE,DISK_READS,sql_text FROM v$sqlarea 
order BY disk_reads DESC )where ROWNUM<10 ; 

--查询Oracle正在执行的sql语句及执行该语句的用户
SELECT b.sid oracleID,
       b.username 登录Oracle用户名,
       b.serial#,
       spid 操作系统ID,
       paddr,
       sql_text 正在执行的SQL,
       b.machine 计算机名
FROM v$process a, v$session b, v$sqlarea c
WHERE a.addr = b.paddr
   AND b.sql_hash_value = c.hash_value
--查看正在执行sql的发起者的发放程序
SELECT OSUSER 电脑登录身份,
       PROGRAM 发起请求的程序,
       USERNAME 登录系统的用户名,
       SCHEMANAME,
       B.Cpu_Time 花费cpu的时间,
       STATUS,
       B.SQL_TEXT 执行的sql
FROM V$SESSION A
LEFT JOIN V$SQL B ON A.SQL_ADDRESS = B.ADDRESS
                   AND A.SQL_HASH_VALUE = B.HASH_VALUE
ORDER BY b.cpu_time DESC
--查出oracle当前的被锁对象
SELECT l.session_id sid,
       s.serial#,
       l.locked_mode 锁模式,
       l.oracle_username 登录用户,
       l.os_user_name 登录机器用户名,
       s.machine 机器名,
       s.terminal 终端用户名,
       o.object_name 被锁对象名,
       s.logon_time 登录数据库时间
FROM v$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#;

--kill掉当前的锁对象可以为

alter system kill session \'sid， s.serial#‘;