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Re: Why skolemization?

From: Sandro Hawke <sandro@w3.org>
Date: Wed, 30 Mar 2011 08:51:27 -0400
To: Richard Cyganiak <richard@cyganiak.de>
Cc: Steve Harris <steve.harris@garlik.com>, semantic-web@w3.org
Message-ID: <1301489487.2139.732.camel@waldron>
On Wed, 2011-03-30 at 17:56 +0530, Richard Cyganiak wrote:
> On 27 Mar 2011, at 18:17, Sandro Hawke wrote:
> > If I say
> >        store.load("http://example.org/g1")
> >        store.load("http://example.org/g2")
> > and g1 and g2 happen to return the same g-text containing bnodes, maybe:
> >        _:x foaf:knows _:y
> > then yeah, we'll have to Skolemize them differently.
> > 
> > But if I say:
> >        store.load("http://example.org/g1")
> > and then repeat it:
> >        store.load("http://example.org/g1")
> > and it get the same g-text, I think it's appropriate for the store to
> > use the same Skolem constants.
> 
> That's an implementation issue. If a store wants to do something smart to skolemize to the same constant, fine. But that's orthogonal to the discussion here.

Yes, it's an implementation issues, but I don't think it's orthogonal,
because it speaks to the practicalities of Skolemizing.   I think the
main problem with Skolemizing is that you can generate a great many
low-value, redundant URIs.  By flagging them, folks downstream are more
seriously encouraged to try to collapse them.   But if we don't do some
collapsing at the start, I don't think I'm comfortable with suggesting
folks do this at all.

So I was hoping people knew some good techniques for collapsing them
(or, equivalently, safely reusing them).    Unfortunately, I don't think
there are good solutions here.

    -- Sandro
Received on Wednesday, 30 March 2011 12:51:38 UTC

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