How to translate the value of state in the X$BH?

Are the following assumption correct??

SQL> select state, count(*)
  2 from x$bh
  3 group by state;

STATE COUNT(*) Assumption

---------     ---------       --------------------
        0         2         Total blocks NOT been used ?
        1      3968      Total blocks  used ?
        3        30         ?
             ----------
              4000         Total DB_BLOCK_BUFFERS

Regards,

Reza Abouk Received on Fri Mar 07 1997 - 00:00:00 CST