I have set up a trigger which checks against a field in a table and
denies the operation if the field is exceeded.

Since the db and the trigger is created as SYSDBA, I do not wish the
SYSDBA password to be reset (by someone with root access) so that
someone can modify the (or drop) the trigger to get round the restriction.

Is this possible at all. I suppose indirectly, the question should be,
can I prevent the SYSDBA password from being reset by a user (with
root access).

Cheers
-raj