/*显示当前用户*/
show user
在sql plus中可用，在pl sql中不可用

/*查看所有用户名*/　
select?username,user_id,created?from?all_users;

/*查看当前用户的用户详情*/　
select?username,user_id,account_status,lock_date,expiry_date,default_tablespace,temporary_tablespace,created,initial_rsrc_consumer_group,external_name?from?user_users;

/*查看数据库的版本*/　
select product,version,status from product_component_version;

/*查看当前用户的用户权限，系统权限和表级权限*/　
select username,granted_role,admin_option,default_role,os_granted from user_role_privs;
select username,privilege,admin_option from user_sys_privs;
select grantee,owner,table_name,grantor,priviege,granttable,hierarchy from user_tab_privs;

查看当前用户的缺省表空间
SQL>select username,default_tablespace from user_users;

　　查看当前用户的角色
SQL>select * from user_role_privs;

　　查看当前用户的系统权限和表级权限
SQL>select * from user_sys_privs;
SQL>select * from user_tab_privs;

　　查看用户下所有的表
SQL>select * from user_tables;

　　显示用户信息(所属表空间)
select default_tablespace,temporary_tablespace?
from dba_users where username='GAME';

　　1、用户

　　查看当前用户的缺省表空间
SQL>select username,default_tablespace from user_users;

　　查看当前用户的角色
SQL>select * from user_role_privs;

　　查看当前用户的系统权限和表级权限
SQL>select * from user_sys_privs;
SQL>select * from user_tab_privs;

　　显示当前会话所具有的权限
SQL>select * from session_privs;

　　显示指定用户所具有的系统权限
SQL>select * from dba_sys_privs where grantee='GAME';

　　显示特权用户
select * from v$pwfile_users;

　　显示用户信息(所属表空间)
select default_tablespace,temporary_tablespace?
from dba_users where username='GAME';

　　显示用户的PROFILE
select profile from dba_users where username='GAME';

　　
2、表

　　查看用户下所有的表
SQL>select * from user_tables;

　　查看名称包含log字符的表
SQL>select object_name,object_id from user_objects
where instr(object_name,'LOG')>0;

　　查看某表的创建时间
SQL>select object_name,created from user_objects where object_name=upper('&table_name');

　　查看某表的大小
SQL>select sum(bytes)/(1024*1024) as "size(M)" from user_segments
where segment_name=upper('&table_