Free & Used Space in Tablespace from SQL

Run this sql statement SELECT /* + RULE */  df.tablespace_name "Tablespace",        df.bytes / (1024 * 1024) "Size (MB)",        SUM(fs.bytes) / (1024 * 1024) "Free (MB)",        Nvl(Round(SUM(fs.bytes) * 100 / df.bytes),1) "% Free",        Round((df.bytes - SUM(fs.bytes)) * 100 / df.bytes) "% Used"   FROM dba_free_space fs,        (SELECT tablespace_name,SUM(bytes) bytes           FROM dba_data_files          GROUP BY tablespace_name) df  WHERE fs.tablespace_name (+)  = df.tablespace_name  GROUP BY df.tablespace_name,df.bytes UNION ALL SELECT /* + RULE */ df.tablespace_name tspace,        fs.bytes / (1024 * 1024),        SUM(df.bytes_free) / (1024 * 1024),        Nvl(Round((SUM(fs.bytes) - df.bytes_used) * 100 / fs.bytes), 1),        Round((SUM(fs.bytes) - df.bytes_free) * 100 / fs.bytes)   FROM dba_temp_files fs,        (SELECT tablespace_name,bytes_free,bytes_used           FROM v$temp_space_header          GROUP BY tablespace_name,bytes_free,bytes_used) df  WHERE fs.tablespace_name (+)  = df.tablespace_name  GROUP BY df.tablespace_name,fs.bytes,df.bytes_free,df.bytes_used  ORDER BY 4 DESC;