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RE: Statements/Reified statements

From: Damien Morton <Morton@dennisinter.com>
Date: Fri, 24 Nov 2000 11:45:10 -0500
Message-ID: <943410FA2AAED4119D4A00508BFC8959020D6A@MAILSERVER>
To: www-rdf-interest@w3c.org

I recently subscribed to the RDF list, and have been doing my reading on RDF
for a while now.

I hope you will forgive me if I ask a question or two.

If an rdf database contains a set (s,p,o) statements, how is ordering meant
to be implemented?

I see that the predicate rdf_n is used in rdf sequences, but surely when an
object is inserted into a collection at some position, all of the rdf_n
predicates will have to be renumbered to reflect the new ordering. Is my
understanding correct? Isnt this something of an implementation nightmare,
causing a single insertion or deletion to require re-stating of all of the
membership statements about the collection.

If one were to restate all of the membership statements, how would you query
for "x: (container, rdf_n, ?x)", given that you dont know what n is, and
that you probably dont want to be doing regular expression searches on
predicates.

Surely a better way would be to implement this as a linked list of
statements.



> -----Original Message-----
> From: Bill de hÓra [mailto:dehora@acm.org]
> Sent: Thursday, November 23, 2000 3:21 PM
> To: www-rdf-interest@w3c.org
> Subject: Re: Statements/Reified statements
> 
> 
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> : Bag <-type- A -rdf_1-> B           =        Bag <-type- A -rdf_1->
> C
> :               -rdf_2-> C                                  -rdf_2->
> B
> :
> : It makes sense to ask whether some resource is a member of a bag.
> Does it make sense
> : to ask a resource, to be the "second" member of a bag?
> 
> No. A bag has no natural ordering. Containers use this notation to
> identify members, it is a bit confusing but you get used to it. You
> can call this an "artefact" of the model/xml.
> 
> - -Bill de hÓra
Received on Friday, 24 November 2000 11:42:27 GMT

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