select * from v$sqlarea t where t.PARSING_SCHEMA_NAME in ('用户名') order by t.LAST_ACTIVE_TIME desc
select * from v$sqlarea t order by t.LAST_ACTIVE_TIME desc

select * from v$sqlarea t where ( to_char(t.LAST_ACTIVE_TIME,'yyyy-mm-dd hh24:mi:ss') > '2011-12-28 14:11:39' ) and (to_char(t.LAST_ACTIVE_TIME,'yyyy-mm-dd hh24:mi:ss') < '2011-12-28 14:11:43') order by t.LAST_ACTIVE_TIME desc

select sysdate from dual

select * from v$locked_object;
select b.owner,b.object_name,a.session_id,a.locked_mode from v$locked_object a,dba_objects b where b.object_id = a.object_id;
select b.username,b.sid,b.serial#,logon_time from v$locked_object a,v$session b where a.session_id = b.sid order by b.logon_time;

select * from dba_outstanding_alerts

select * from v$locked_object

select sid,id1,type from v$lock where id1=(select object_id from dba_objects where object_name=upper('mytablename'));

select saddr,sid,serial#,paddr,username,status from v$session where sid=772

SQL> alter system kill session '772,9044';
System altered.

select spid, osuser, s.program from v$session s,v$process p
where s.paddr=p.addr and s.sid=772

SQL> alter system kill session '1034,3545'
2 /
alter system kill session '1034,3545'
*
ERROR at line 1:
ORA-00031: session marked for kill
SQL> select spid, osuser, s.program from v$session s,v$process p
2 where s.paddr=p.addr and s.sid=1034
3 /
SPID OSUSER
------------ ------------------------------
PROGRAM
------------------------------------------------
303424 oracle
oracledv@p5a2 (TNS V1-V3)
DB1@/home/oracle>su - root
p5a1@/#kill -9 303424
p5a1@/#ps -ef|grep 303424
root 574442 376852 0 23:06:09 pts/1 0:00 grep 303424

--转自

Error Id: ORA-00031

Title: session marked for kill

Description:

session marked for kill

Action:

No action is required for the session to be killed, but further executions of the ALTER SYSTEM KILL SESSION command on this session may cause the session to be killed sooner.

Cause:

The session specified in an ALTER SYSTEM KILL SESSION command cannot be killed immediately (because it is rolling back or blocked on a network operation), but it has been marked for kill. This means it will be killed as soon as possible after its current uninterruptable operation is done.

-- 来自：