Serious pb with INDEX_HISTOGRAM

Hi,
How do you explain this: I have a table XXX SQL> desc XXX

 Name                         Null?    Type
 ---------------------------- -------- ------------------
 ...
 KM_DENORM                             NUMBER(18)

that contains 264911 rows. This field above is indexed because *it contains 264911 different values* (=> count(1)/count(distinct km_denorm) = 1). Yet when I do an ANALYZE INDEX VALIDATE STRUCTURE, I get:

REPEAT_COUNT KEYS_WITH_REPEAT_COUNT

------------ ----------------------
           0                      0
           1                 264911
           2                      0
           3                      0
           4                      0
       [...]
          15                      0

with SELECT * FROM index_histogram. How do you explain this ? My index is NEVER used, there's obviously no way of forcing the optimizer to use it (whatever the INDEX() hint I use). For ex. I'd like to be able to get a very quick answer to (the other index on XXX.VEHID works fine): SELECT (...)
FROM XXX KM
WHERE KM.km_denorm = (SELECT MAX(D2.km_denorm)

                      FROM XXX D2
                      WHERE D2.VEHID=KM.VEHID)

The values look like the following:
SQL> select min(KM_DENORM), max(km_denorm) from XXX;

          KM_DENORM KM_DENORM

------------------- -------------------
     19720101009089      20021217272582

Any idea ?
Thanks a lot...
Sp Received on Mon Jan 27 2003 - 09:53:15 CST