Data Files free space

Create Or Replace Force View Sys.Av_db_df_free_space (Tablespace_name,
                                                      File_name,
                                                      Allocated_mb,
                                                      Used_mb,
                                                      Free_space_mb
                                                     )

As
   Select   Dfs.Tablespace_name, Substr (Df.Name, 1, 40) File_name,
            Df.Bytes / 1024 / 1024 Allocated_mb,
            ((Df.Bytes / 1024 / 1024) - Nvl (Sum (Dfs.Bytes) / 1024 / 1024, 0)
            ) Used_mb,
            Nvl (Sum (Dfs.Bytes) / 1024 / 1024, 0) Free_space_mb
       From V$datafile Df, Dba_free_space Dfs
      Where Df.File# = Dfs.File_id(+)
   Group By Dfs.Tablespace_name, Dfs.File_id, Df.Name, Df.File#, Df.Bytes
   Order By Dfs.Tablespace_name;