ALTER TABLE site_node_object_mappings ADD CONSTRAINT snom_object_id_fk FOREIGN KEY (object_id) REFERENCES acs_objects (object_id) ON UPDATE CASCADE ON DELETE CASCADE;
And edit the initial install SQL script, too, if you do! :)
The same ALTER TABLEs should work on oracle EXCEPT that Oracle does not support ON UPDATE CASCADE, only ON DELETE CASCADE.
If you can edit initial install and upgrade scripts for Oracle, too, and afterwards e-mail honchos I'm sure you can get daveb to test it ...
or me ...