W3C home > Mailing lists > Public > www-rdf-interest@w3.org > July 2003

Re: URIQA questions

From: Benja Fallenstein <b.fallenstein@gmx.de>
Date: Tue, 08 Jul 2003 00:54:49 +0200
Message-ID: <3F09FA39.2040002@gmx.de>
To: "Thomas B. Passin" <tpassin@comcast.net>
CC: www-rdf-interest@w3.org


Thomas B. Passin wrote:
> [Benja Fallenstein]
>>Ok. So URIQA makes the following design decisions:
>> ...
>>- In particular, it doesn't provide a way to query the server for
>>additional information that may be necessary to understand the
>>abovementioned subset of a URI's authoritative information.
> But for any resource that did get returned in the concise bounded
> description, you can ask for a concise bounded description of __it__.

But only if it's in the authority of the same server. So if you have

     ex:Foo   rdfs:subClassOf   ex:Bar
     ex:Bar   ont:warning       "Hazardrous!"

everything is fine, but if it is

     ex:Foo   rdfs:subClassOf   fy:Bar
     fy:Bar   ont:warning       "Hazardrous!"

(in the knowledge base of the ex:... server) you cannot access the 
latter triple (assuming that the fy:... server doesn't also have it). It 
cannot be considered authoritative knowledge about fy:Bar, but it can be 
considered authoritative about ex:Foo!

Worse, if you have

     ex:Foo   rdfs:subClassOf   <urn:urn-5:gK0wObL42bRyFllUsU+8cPL5cQBi>
     <urn:urn-5:gK0wObL42bRyFllUsU+8cPL5cQBi>  ont:warning  "Hazardrous!"

there is no way to get the latter triple, even if it is what the person 
who minted the URN thought, since there is no authority for urn-5 URIs.

I happen to use this, so URIQA really doesn't work for my data.

> If the server knows about it, you get what you need.  If the server does not
> know about it, you would not get any information about it even with a fuller
> query. 

Hey, I gave two cases at the beginning of this thread where this isn't 
the case, and Patrick essentially said, "you cannot do this and it's 

1st case: The URI I have is the object of a triple containing the 
information I need.

2nd case: The information I need is more than one step away from the URI 
I have, and there's another URI on the way which is in the authoritative 
domain of another server (or no server at all).

In both of these cases, a fuller query would return the information alright.

- Benja
Received on Monday, 7 July 2003 18:56:15 UTC

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