@dirtbikermp3: db-file is trail-database I assume ? (xxx-xxxxx-xx.db)
You write that the trail-database has nothing to do with active routing. I think You mean the routing on the map.
In my opinion the database is necessary for searching. I can't give it a try on a modern gps (i don't own one), but in Basecamp I can search for a Trail with a name (in dutch: Paden met naam zoeken) and use that kind of trails in my routes (single or combined as a part of my own trails).
When I rename the db-file in the addition-map (of the gmap installation) I can't search in Basecamp for Trails with a name: Basecamp cann't find any Trail. I guess that will be the same situation on a suitable modern gps that supported these kinds of maps.