V$WAITSTAT

Columns
   ___________________________
 
   COUNT
   TIME
   CLASS


A related X$ view worth looking at is X$KCBFWAIT:

columns:
   ADDR 
   INDX 
   COUNT
   TIME

You can use this to display Buffer Waits per file
(run as SYS)

SELECT count, time, name
FROM v$datafile df, X$KCBFWAIT fw
WHERE fw.indx+1 = df.file#;

-- Tip taken from Jonathan's Book

Related Views:

V$DATAFILE
V$FILESTAT