如何查看oracle表空间

select tablespace_name,sum(bytes)/1024/1024 from dba_data_files  group by tablespace_name
select tablespace_name,sum(bytes)/1024/1024 from dba_free_space group by tablespace_name;

--查看所有表空间
select tablespace_name,bytes/1024/1024 from dba_data_files  

--查看未使用表空间大小
select tablespace_name,bytes/1024/1024  from dba_free_space