SQL>
SQL> select Class,
2 Count
3 from V$WAITSTAT;
CLASS COUNT
------------------ ----------
data block 38
sort block 0
save undo block 0
segment header 0
save undo header 0
free list 0
extent map 0
1st level bmb 0
2nd level bmb 0
3rd level bmb 0
bitmap block 0
bitmap index block 0
file header block 1
unused 0
system undo header 0
system undo block 0
undo header 1
undo block 0
18 rows selected.
SQL>