System Tables Views Oracle PLSQL

SQL>
SQL> select DF.Name File_Name,
  2         FS.Phyblkrd Blocks_Read,
  3         FS.Phyblkwrt Blocks_Written,
  4         FS.Phyblkrd+FS.Phyblkwrt Total_IOs
  5    from V$FILESTAT FS, V$DATAFILE DF
  6   where DF.File#=FS.File#
  7   order by FS.Phyblkrd+FS.Phyblkwrt desc;
FILE_NAME
------------------------------------------------------
BLOCKS_READ  BLOCKS_WRITTEN   TOTAL_IOS
-----------  --------------  ----------
C:\ORACLEXE\ORADATA\XE\SYSTEM.DBF
       4954             405        5359
C:\ORACLEXE\ORADATA\XE\SYSAUX.DBF
       2294             398        2692
C:\ORACLEXE\ORADATA\XE\UNDO.DBF
       1219            1422        2641
C:\ORACLEXE\ORADATA\XE\USERS.DBF
          6               3           9
C:\ORACLEXE\APP\ORACLE\PRODUCT\10.2.0\SERVER\DATABASE\
DATA_1B.DBF
          5               2           7
C:\ORACLEXE\APP\ORACLE\PRODUCT\10.2.0\SERVER\DATABASE\
DATA_1A.DBF
          5               2           7
6 rows selected.
SQL>