Datafile blocks per read

From Oramosswiki

SELECT phyrds
,      phyblkrd
,      ROUND((phyblkrd / phyrds),2) blocks_per_read
FROM   (SELECT SUM(f.phyrds) phyrds
        ,      SUM(f.phyblkrd) phyblkrd
        FROM   v$filestat f
       )
/