SELECT (d.value/m.value) * 100
  INTO   v_value
  FROM   v$sysstat d,
         v$sysstat m
  WHERE  d.name = 'sorts (disk)'
  AND    m.name  = 'sorts (memory)';

break on report
compute sum of free on report
compute sum of used on report
compute sum of totsz on report
column "(%)" format 999
set feedback off;
set pages 24
select
     a.tablespace_name, sum(round(a.bytes/(1024*1024))) totsz,  sum(used) used, 
     sum(nvl(free,0)) free, 
     round((sum(nvl(free,0))/sum(round(a.bytes/(1024*1024))))*100) "(%)"
from 
    dba_data_files a, 
    (select file_id,round(sum(bytes)/(1024*1024)) used
     from dba_extents group by file_id) b,
    (select tablespace_name,file_id,round(sum(bytes)/(1024*1024))  free
    from dba_free_space group by tablespace_name, file_id) c
where
    a.file_id=b.file_id and a.file_id=c.file_id(+) 
group
    by a.tablespace_name;
set feedback on;