• 查看当前在用DB的用户
• 查看用户正在执行的语句
• 查看锁住的语句
• 查看用户在那个机器链接进来
• 查看哪个Session的CPU占用率最高
• 查看数据库的最大并发链接
• 查看历史最大并发数
• 查看当前并发数
• 查看某个用户所具备的角色和权限
• 查看数据库版本
• 查看patch情况
• 查看服务器端的parameter
• 杀Session
• 看某个Session对应的操作系统PID
• 。。。

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select username,default_tablespace from user_users;
select * from user_role_privs;
select * from user_sys_privs;
select * from user_tab_privs;
select * from user_tables;
select object_name,object_id from user_objects
                where instr(object_name,'LOG')>0;
select object_name,created from user_objects where object_name=upper

('&table_name');
select * from user_sequences;
select view_name from user_views;
select member from v$logfile;
Select version FROM Product_component_version
    Where SUBSTR(PRODUCT,1,6)='Oracle';
用系统管理员，查看当前数据库有几个用户连接：

SQL> select username,sid,serial# from v$session;

如果要停某个连接用

SQL> alter system kill session 'sid,serial#';

如果这命令不行,找它UNIX的进程数

SQL> select pro.spid from v$session ses,v$process pro where ses.sid=21

and ses.paddr=pro.addr;

说明：21是某个连接的sid数

然后用 kill 命令杀此进程号。

select column_name,comments from dict_columns where

table_name='USER_INDEXES';

select column_name,comments from dict_columns where upper(table_name)

='v$session';
如何查看最大会话数？
SELECT * FROM V$PARAMETER WHERE NAME LIKE 'proc%'；
Select * from v$license;
SELECT *  FROM  USER_ERRORS;
SELECT * FROM V$INSTANCE;
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#=11 and c.sid=a.sid and a.paddr=b.addr order by

value desc;

select * from v$sqltext where address = 'C0000001E0B4A160';
select sql_text, piece, hash_value
from v$sqltext
where  address = 'C0000001E0B4A160'
order by hash_value, piece;

select * from v$sqlarea where address = (select sql_address from

v$session where sid = :1);