Oracle查询表占用空间的大小

select * from (select OWNER, segment_name, segment_type, sum(bytes) mmm from dba_segments where /*tablespace_name='SCMPT_TBS'/* and segment_type='TABLE'*/
owner='' and segment_type='TABLE' and segment_name=''
group by OWNER, segment_name,segment_type
order by mmm desc)