From: ccoprmm@oit.gatech.edu (Michael Mealling)
Message-Id: <199307161422.AA17937@oit.gatech.edu>
Subject: Re: URNs in the DNS
To: M.T.Hamilton@lut.ac.uk
Date: Fri, 16 Jul 93 10:22:21 EDT
In-Reply-To: <Pine.3.07.9307161059.C5963-b100000@lust>; from "Martin Hamilton" at Jul 16, 93 1:18 pm
Martin Hamilton said this:
> > With whois++ it's just as easy to add the metadata to a URN/URL
> > pair as it is anything else. I think we could do this fairly easily.
>
> Uh huh - and since the URI field is already in the IAFA templates,
> it would seem sensible to have a separate template to deal with at
> least the URN to URL mapping. I can't recall having seen anything
> along these lines, but perhaps I've not been looking in the right
> places ?
Exactly. This is what I proposed in Washington. You have a template that
has just one URN and multiple URLs which is thrown into whois++ and theres
your mapping function.
Now (and this is where I get into URMs), it makes additional good sense to
add a URM to that list (see below). That way you can get back metainformation
that has been cached by the whois++ server everytime it get's an updated
URL for that specific template. That way you can pass around that whole
template as a stab at a citation that has yet to actually access the resource
in order to get the authoritative metainfo.
> Perhaps we can get away with something as simple as this...
>
> URN-TO-URL-MAPPING:
> URN: // as per current internet draft
> Multiple occurrences of the following block of fields
> URL: // physical address of object
URM: // CACHED but not permanent metainformation
> end of multiple occurrences
> END URN-TO-URL-MAPPING
Note the precedence that this structure generates. A URN 'owns' each URL
below it and a URL 'owns' each URM below that. What you then can do is put
a new URN at the end of that template with it's respective list of
URLs/URMs. This would then give you some way to denote a relationship
between URNs. You could have a template that was designated as all URNs for
each version of a document, each with it's own URN. Then give that template
it's own URN as a pointer to the whole set.
-MM
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