方法1：
select ff.s tablespace_name,
ff.b total,
(ff.b - fr.b) usage,
fr.b free,
round((ff.b - fr.b) / ff.b * 100) || '% ' usagep
from (select tablespace_name s, sum(bytes) / 1024 / 1024 b
from dba_data_files
group by tablespace_name) ff,
(select tablespace_name s, sum(bytes) / 1024 / 1024 b
from dba_free_space
group by tablespace_name) fr
where ff.s = fr.s
方法2：
select a.owner,a.segment_name,segment_type,sum(bytes)/1024 as SizeM From dba_segments a
inner join (
select owner,segment_name from dba_lobs where table_name ='XI_AF_MSG' union all
select owner,index_name as segment_name from dba_indexes where table_name ='XI_AF_MSG' union all
select owner,segment_name from dba_segments where segment_name='XI_AF_MSG'
) b on a.owner=b.owner and a.segment_name=b.segment_name
group by a.owner,a.segment_name,segment_type
order by a.segment_name