Re: [TF:DbE] The easiest keys there are

On 1 Oct 2007, at 11:20, Danny Ayers wrote:

> On 01/10/2007, Bijan Parsia <bparsia@cs.man.ac.uk> wrote:
>>
>> On Sep 28, 2007, at 6:51 PM, Bijan Parsia wrote:
>>
>>> Hi folks,
>>>
>>> The OWLED task force on DatabasEsque features:
>>>       http://code.google.com/p/owl1-1/wiki/DatabasEsque
>>>
>>> Well, at least Uli and me, have been doing a bit of work on keys
>>> (aka, inverseFunctional datatype properties) prompted by a visit to
>>> Manchester by Matthew Pocock. Some sort of keys is a pretty high
>>> value feature.
>
> Hi Bijan,
>
> Quick question, would these 'legitimise', and enable OWL tools to  
> work with
> foaf:mbox_sha1sum (allowing person-identity smushing as with
> foaf:mbox, which is an ObjectProperty IFP)?

Ideally, yes. That is one of the use cases. One bit of research I've  
not yet done is to survey the smushing code out there and see how  
closely it aligns with what we're proposing. My sense, based on my  
old understanding of how smushing generally works, is that it's  
pretty much the same, i.e., missing keys aren't a problem, same key  
causes a merge, multiple keys are ok (i.e., no functional  
constraints), explicit values only, etc. The big difference is that  
FOAF typically works on bnode subjects, which, under standard BNode  
semantics are existential variables, thus wouldn't (technically  
speaking) fall under our proposal.

However, the common, deployed semantics for BNodes is that they are  
local names, not existential variables. SPARQL treats them that way.  
RIF shall as well, I'm pretty sure. SPARQL/OWL probably will. So, we  
should work that fact into the proposal as well.

HTHs.

Cheers,
Bijan.

Received on Monday, 1 October 2007 10:31:54 UTC