Oracle查看表空间大小及使用率

select  

         sysdate,c.tablespace_name,round(used_mb,1),round(total_mb,1),round(used_mb/total_mb,3)*100||'%'

from
         (select tablespace_name, sum(bytes)/1024/1024 used_mb from dba_segments group by tablespace_name) a,
         (select tablespace_name,SUM(case autoextensible  when 'YES' THEN
              CASE WHEN maxbytes > bytes THEN maxbytes ELSE bytes END
              ELSE bytes END)/1024/1024 total_mb
         from dba_data_files group by tablespace_name) b,
         dba_tablespaces c
where

         c.tablespace_name = b.tablespace_name
         and c.tablespace_name=a.tablespace_name(+)
         and c.contents = 'PERMANENT'
         and c.tablespace_name not like '%UNDO%'
order by used_mb/total_mb;