select   a.tablespace_name,a.bytes/1024/1024 "Total MB",(a.bytes-b.bytes)/1024/1024   "used MB",b.bytes/1024/1024 "free MB",round(((a.bytes-b.bytes)/a.bytes)*100,2) "percent_used"  from  (select tablespace_name,sum(bytes) bytes from dba_data_files group by tablespace_name)   a,  (select tablespace_name,sum(bytes) bytes,max(bytes) largest from dba_free_space group by tablespace_name)   b  where   a.tablespace_name=b.tablespace_name  order   by   ((a.bytes-b.bytes)/a.bytes)   desc;