vsize of LONG RAW data

Oracle People:

I've had a bad time trying to find the size of the rows of a BLOB table. I got so far as to realize the "VSIZE" function could help-

But, it won't work on LONG RAW DATA:

SQL> select count(*), vsize(DATA) from cq06.user_blob;
select count(*), vsize(DATA) from cq06.user_blob
*
ERROR at line 1:
ORA-00997: illegal use of LONG datatype
-----------------------

Here is the "desc" of the offending table:

SQL> desc cq06.user_blob;
Name Null? Type
----------------------------------------- -------- ---------------------------- DBID NUMBER(10)
DATA LONG RAW


I'd really like to know the size of all the entries of DATA.

Thanx,

Roger