W3C home > Mailing lists > Public > semantic-web@w3.org > January 2008

Re: plural vs singular properties (a proposal)

From: Frank Manola <fmanola@acm.org>
Date: Sat, 5 Jan 2008 17:55:02 -0500
Message-Id: <6D57E9F0-5C7A-48C2-A503-950B34A5505D@acm.org>
Cc: SWIG <semantic-web@w3.org>
To: Garret Wilson <garret@globalmentor.com>


On Jan 5, 2008, at 5:11 PM, Garret Wilson wrote:

> Frank, thank you *very* much for your clarifications; they help  
> immensely. Just a couple more comments below:
>
> Frank Manola wrote:
>>
>>>
>>> 3. The semantics of the relational model when "interpreted in an  
>>> obvious way" by Date in his wine example is an interpretation  
>>> incompatible with and therefore unsuitable for representing RDF  
>>> because it does not allow each predicate to be duplicated in the  
>>> relation header.
>>
>> I don't think it's a matter of the interpretation being  
>> incompatible.  The relational model simply requires that when you  
>> have a situation in which it appears a predicate must be repeated  
>> (or a single predicate must have multiple values), you must define  
>> a separate relation.
>
> Yes, obviously some RDF subsets can be mapped to the relational  
> model in several ways. As relating to my original question, though,  
> I could not choose the semantics "interpreted in an obvious way" by  
> Date as a way to support general RDF data. In other words, Date's  
> interpretation is *only* compatible with storing a *strict subset*  
> of RDF data; there exists RDF data that would not fit into this  
> interpretation. This is the sense in which I meant that this  
> interpretation (let's call it the "obvious" interpretation, using  
> Date's words) is incompatible with RDF (the model) as a general  
> interpretation, because it cannot represent everything expressible  
> by RDF.

Sorry, I'm not following you.  Could you give an example of RDF data  
that wouldn't fit?  What I thought I just heard you say was that the  
relational model can't represent everything that's expressible by  
RDF, and that certainly isn't true (RDF can be thought of as a  
relational model that follows particular design rules).  [I'll take  
this thread up again tomorrow;  it's football time now!]
Received on Saturday, 5 January 2008 22:55:17 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 21:45:20 GMT