Oracle: disk reads

Taking a general gauge on disk reads.

tttile "Disk Read Write" col phyrds format 999,999,999; 
col pyywrits format 999,999,999; 
col readtim format 999,999,999; 
col writetim format 999,999,999; col name format a60;
select name, phyrds, phywrts, readtim, writetim from v$filestat a, v$datafile b where a.file#=b.file# order by 3 desc;