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Re: Portability of data Re: Upcoming wave of quads

From: Sandro Hawke <sandro@w3.org>
Date: Fri, 10 Sep 2004 08:23:41 -0400
Message-Id: <200409101223.i8ACNfSs007529@roke.hawke.org>
To: Charles McCathieNevile <charles@w3.org>
cc: Andrew Newman <andrew@tucanatech.com>, www-rdf-interest@w3.org


> On Fri, 10 Sep 2004, Andrew Newman wrote:
> 
> >The main problem we've had with named graphs is that it can be a pain on
> >a machine that has multiple names or names that change over time.  If I
> >create a models based on machine names called "http://192.168.10.1/foo"
> >and then move to another network and suddenly it's
> >"http://10.0.0.42/foo" then all my existing queries stop working.  I now
> >prefer URNs for models not URIs and add a level of indirection between
> >them (I think this has been mentioned before).
> 
> That just feels like a bug - at least at the usability level. Surely it is
> sensible to change machines and be able to use the same data (at least as a
> possiblity and I would have thought even as a default) including queries?

Suggested Best Practice: when making up URIs to name things, only use
URIs which you'll likely be able to respond to for the maximum
expected lifetime of your data.   purl.org is a good approach if you
have no confidence in your own domain name.   When you really can't do
that, use a b-node, but try hard not to, since b-nodes don't allow
easy graph connections.

This is orthogonal to named-graphs/quads -- it applies just as well to
assigning URIs to the usual things (dogs, cars, and coffee-makers, of
course :-).

       -- sandro
Received on Friday, 10 September 2004 12:21:11 GMT

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