1 select * from session_privs;--查看当前用户的所有权限
2 select * from tab where tabtype='TABLE';--查看当前用户下的所有表
3
4 commit;　　　 --结束上一个事务 并且开始一个新的事务
5 update student set sal = null where xh =1000;
6 savepoint c111;
7 insert into student(xh,name,sex) values (1004,'MIKE','男');
8 rollback to c111; --撤销了插入的数据
9 rollback;　

1.select t2.username,
2.       t2.sid,
3.       t2.serial#,
4.       t3.object_name,
5.       t2.OSUSER,
6.       t2.MACHINE,
7.       t2.PROGRAM,
8.       t2.LOGON_TIME,
9.       t2.COMMAND,
10.       t2.LOCKWAIT,
11.       t2.SADDR,
12.       t2.PADDR,
13.       t2.TADDR,
14.       t2.SQL_ADDRESS,
15.       t1.LOCKED_MODE
16.  from v$locked_object t1, v$session t2, dba_objects t3
17. where t1.session_id = t2.sid
18.   and t1.object_id = t3.object_id
19. order by t2.logon_time;  

 1 -查某session 正在执行的sql语句，从而可以快速定位到哪些操作或者代码导致事务一直进行没有结束等.
 2 SELECT /*+ ORDERED */
 3  sql_text
 4   FROM v$sqltext a
 5  WHERE (a.hash_value, a.address) IN
 6        (SELECT DECODE(sql_hash_value, 0, prev_hash_value, sql_hash_value),
 7                DECODE(sql_hash_value, 0, prev_sql_addr, sql_address)
 8           FROM v$session b
 9          WHERE b.sid = '233')  /* 此处233 为SID*/
10  ORDER BY piece ASC;
11
12
13 --查进程.
14 select * from v$process ;
15
16
17 --查锁18    select * from v$lock;
19
20 --查锁定的对象
21 select * from v$locked_object
22
23 --查事务
24 select * from v$transaction
25
26 --查session
27  select v.* from v$session v where machine='xxx' and username='xxx' and status='INACTIVE' order by last_call_et desc
28
29 --查dba_objects对象
30 select * from dba_objects
31 where object_id = '14977'
32
33 --查锁定的表
34  select t2.username,t2.sid,t2.serial#,t3.object_name,t2.OSUSER,t2.MACHINE,t2.PROGRAM,t2.COMMAND,t2.LAST_CALL_ET
35         from v$locked_object t1,v$session t2 ,dba_objects t3
36         where t1.session_id=t2.sid  and t1.object_id = t3.object_id
37         order by t2.logon_time;