oracle 表空间查询

sum(remainedM) 剩余空间M,
sum(usedM) / sum(totalM)*100 占用百分比,
sum(remainedM)/sum(totalM)*100 剩余百分比
from (
select b.file_id ID,
b.tablespace_name tbs,
b.file_name name,b.bytes/(1024*1024) totalM,
(b.bytes-sum(nvl(a.bytes,0)))/(1024*1024) usedM,
sum(nvl(a.bytes,0))/1024/1024 remainedM,
sum(nvl(a.bytes,0))/(b.bytes)*100 剩余百分比,
(100-(sum(nvl(a.bytes,0))/(b.bytes)*100)) 占用百分比
from dba_free_space a,dba_data_files b where a.file_id=b.file_id group by
b.tablespace_name,b.file_name,b.file_id,b.bytes order by b.tablespace_name) group by
tbs;