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Re: Indicating Skolem Nodes (was Re: AW: {Disarmed} Re: blank nodes (once again))

From: Ivan Herman <ivan@w3.org>
Date: Wed, 30 Mar 2011 16:02:20 +0530
Cc: David Booth <david@dbooth.org>, Pat Hayes <phayes@ihmc.us>, Sandro Hawke <sandro@w3.org>, semantic-web@w3.org
Message-Id: <E2859A6D-61F6-4A5A-AE7A-55D42D9A0882@w3.org>
To: Steve Harris <steve.harris@garlik.com>

On Mar 30, 2011, at 15:55 , Steve Harris wrote:

> I could imagine such a system being quite a significant cost to run in the future, but right now the number of people doing follow-your-nose style linked data walking is minimal.
> 
> Suppose a future bnode.me were as popular as google.com is now, it would require something on the order of a 200 Mbps internet connection just for the responses. That's affordable as a community donation for a medium sized company, but not the sort of thing many individuals would want to fund.
> 

And I do not think the idea would be that individuals would set up such a domain/machine but, say, there is a dedicated domain (and, later, a separate machine) set up at W3C. That does not seem to be unimaginable

Ivan, who has not checked this with the system people, who may ban him for life for this...


> - Steve, who's spent too much of his life doing hosting-costs maths.

:-)

> 
> On 2011-03-30, at 04:51, Ivan Herman wrote:
> 
>> David,
>> 
>> are all those metadata necessary at all? After all, the idea starts with bnodes which, by definition, don't have any type of additional information attached to them by default. So why bother about their skolemized version in this respect? My feeling is that if we did some
>> 
>> http://bnode.me/{UUID} (or http://bnode.me#{UUID})
>> 
>> type URI-s, then dereferencing that URI would return something as similar like
>> 
>> "this UUID is for a blank node"
>> 
>> that is it. Ie, a simple PHP program can return a trivial information in, say, turtle, if you dereference that URI. Because it does not generate anything else, that PHP stuff might become dead simple.
>> 
>> I wonder whether a service running that minimal response would still create as big a load as Sandro fears.
>> 
>> Ivan
>> 
>> 
>> On Mar 26, 2011, at 19:54 , David Booth wrote:
>> 
>>> On Fri, 2011-03-25 at 23:05 -0500, Pat Hayes wrote:
>>>> On Mar 25, 2011, at 10:44 PM, David Booth wrote:
>>>>> Please, at *least* make it dereferenceable to *some* kind of useful
>>>>> information.
>>>> 
>>>> How? These are supposed to be automatically generated and globally
>>>> unique. Will you have the skolemizing process also generate a web page
>>>> somewhere, one for each skolem constant? 
>>> 
>>> No, you're missing my point.  I'm not talking about millions of
>>> auto-generated pages.  I'm talking about information about the
>>> skolomization process *itself*.  In the very least, the URI could point
>>> to the skolomization *specification* that was followed in generating
>>> it.  
>>> 
>>> Presumably, the entire reason for *standardizing* a way of skolomizing
>>> bnodes is to permit RDF consumers to syntactically *recognize* those
>>> URIs as being skolomized bnodes and potentially do something special
>>> with them.  (Otherwise generators could just use whatever process they
>>> wanted, and there would be no need for us to discuss it.)  
>>> 
>>> Hence, it would be helpful to give the RDF consumer who comes across one
>>> of these special URIs the *option* of easily derefererencing it to learn
>>> how it was generated and what information can be reliably concluded
>>> about it by syntactic inspection.  
>>> 
>>> There are many possibilities for what this information might include,
>>> some of it mentioned already, such as:
>>> 
>>> - The fact that this *is* a skolomized bnode URI.
>>> 
>>> - The datetime when it was generated.
>>> 
>>> - Who generated it.
>>> 
>>> - What algorithm was used.
>>> 
>>> This is similar to the idea of having an XML namespace document be
>>> dereferenceable to information about that namespace, although in this
>>> case the information would be about the URI itself rather than being
>>> about the thing that it represents semantically in an RDF graph.
>>> 
>>> BTW, lest anyone think this would violate the principle of URI opacity
>>> http://www.w3.org/TR/webarch/#uri-opacity
>>> it would not, because the whole point is that the information would be
>>> specifically licensed -- not guessed.
>>> 
>>> 
>>> -- 
>>> David Booth, Ph.D.
>>> http://dbooth.org/
>>> 
>>> Opinions expressed herein are those of the author and do not necessarily
>>> reflect those of his employer.
>>> 
>>> 
>> 
>> 
>> ----
>> Ivan Herman, W3C Semantic Web Activity Lead
>> Home: http://www.w3.org/People/Ivan/
>> mobile: +31-641044153
>> PGP Key: http://www.ivan-herman.net/pgpkey.html
>> FOAF: http://www.ivan-herman.net/foaf.rdf
>> 
>> 
>> 
>> 
>> 
> 
> -- 
> Steve Harris, CTO, Garlik Limited
> 1-3 Halford Road, Richmond, TW10 6AW, UK
> +44 20 8439 8203  http://www.garlik.com/
> Registered in England and Wales 535 7233 VAT # 849 0517 11
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> 


----
Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
mobile: +31-641044153
PGP Key: http://www.ivan-herman.net/pgpkey.html
FOAF: http://www.ivan-herman.net/foaf.rdf






Received on Wednesday, 30 March 2011 10:32:35 UTC

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