Another take on 'persistence' and 'indirection'

I've noodled on the questions of persistence of identifiers, waht is a "resource" and so on for a while; http://www.ietf.org/id/draft-masinter-dated-uri-07.txt  is the latest edition of a "thought experiment".  If a 'data:' URI is an immediate address, is a "tdb" URI an indirect one?