[Zope] Do objects have exist in DB to be shown in tree?

Hi, How is traversing the ZODB managed? Does Zope look up the root object and ask it to (recursively) return a given child, or does it go through the physical data itself? I need to create a "folder" with subobjects mirrored from another folder, so my subobjects won't be existing in the DB before somebody modifies their values and saves the changes. Is this at all possible? best, Jacob