oracle8.1.6
delete from bboard_forum_message_map bfm
where message_id in (select message_id
from acs_messages m
connect by prior message_id = reply_to
start with message_id = :message_id)
and exists (select 1 from acs_object_party_privilege_map
where object_id = bfm.message_id
and party_id in (:user_id, -1)
and privilege = 'bboard_delete_message')