Tablespace used and free space check

set pages 100
column tablespace_name format a20
column allocated format 99999999.99
column free format 999999.99
column used format 999999.99
col Contiguous format 999999.99
break on report
compute sum of allocated on report
compute sum of used on report
compute sum of free on report
compute sum of contiguous on report
ttitle  'REPORT ON TABLESPACE DETAILS' skip 2

select rpad(a.tablespace_name,20,'.')tablespace_name,
   sum(a.bytes)/(1024*1024) Allocated,
   sum(a.bytes)/(1024*1024) - max(nvl(b.space,0)) Used,
   max(nvl(b.space,0)) Free,round(((max(nvl(b.space,0)))/(sum(a.bytes)/(1024*1024))),4)*100 perctfree,
   max(nvl(b.cont,0))/(1024*1024)  Contiguous
from dba_data_files a,
   (select tablespace_name,sum(bytes)/(1024*1024) space,max(bytes) cont
    from dba_free_space
    group by tablespace_name) b
where a.tablespace_name = b.tablespace_name(+)
group by a.tablespace_name
/