V$WAITSTAT
Data Dictionary ViewColumns ___________________________ CLASS COUNT TIME
A related X$ 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#;
Related: