select tablespace_name, SizeMb, FreeMb, (FreeMb/SizeMb)*100 PercentFree from ( select b.tablespace_name, tbs_size SizeMb, a.free_space FreeMb from (select tablespace_name, round(sum(bytes)/1024/1024 ,2) as free_space from dba_free_space group by tablespace_name) a, (select tablespace_name, sum(bytes)/1024/1024 as tbs_size from dba_data_files group by tablespace_name) b where a.tablespace_name(+)=b.tablespace_name and a.tablespace_name = 'SCB_CRO'