select * from sys.dba_tablespaces; 查询表空间
select * from v$tablespace; 查询表空间一些参数
select * from dba_users; 查询用户
drop user user_name cascade; 删除用户
drop tablespace tablespace_name including contents and datafiles; 删除表空间
alter tablespace tablespace_old_name rename to tablespace_new_name;