--1、查看表空间的名称及大小 
select
  t.tablespace_name,
  round(sum(bytes/(1024*1024)),0) ts_size 
from 
  dba_tablespaces t, 
  dba_data_files d 
where 
t.tablespace_name = d.tablespace_name 
group by t.tablespace_name; --

2、查看表空间物理文件的名称及大小 
select 
  tablespace_name, 
  file_id, file_name, 
  round(bytes/(1024*1024),0) total_space 
from 
dba_data_files 
order by tablespace_name;