W3C home > Mailing lists > Public > public-rdf-wg@w3.org > September 2012

Re: Why blank nodes?

From: Antoine Zimmermann <antoine.zimmermann@emse.fr>
Date: Fri, 07 Sep 2012 12:41:26 +0200
Message-ID: <5049CF56.2050700@emse.fr>
To: Steve Harris <steve.harris@garlik.com>
CC: "public-rdf-wg@w3.org WG" <public-rdf-wg@w3.org>
Le 07/09/2012 12:35, Steve Harris a écrit :
> Taking a step back, and thinking about what we (Experian) actually use bNodes for, to inform our position on the various scope questions.
>
> Basically, it's just a replacement for auto_increment columns in SQL.
>
> There are two motivations for this
>
> 1) it saves the data generating process from minting a globally unique identifier for it
> 2) it's more efficient in the store, as there's no need to store a text symbol for it
>
> This has been helped by Skolem URIs, as now we have an easy way to refer to them between SPARQL queries.
>
> Any other features of bNodes are just a distraction or inconvenience really.
>
> I'm sure other people have different reasons for using them, anyone care to share?


Bnodes are an absolute requirement for OWL to be serialised in RDF. 
Without bnodes, it would be impossible to define an RDF-based semantics 
for OWL which is (mostly) compatible with the direct semantics.

Bnodes are very often used to express n-ary relations.

rdf:List without bnodes would be insane.



-- 
Antoine Zimmermann
ISCOD / LSTI - Institut Henri Fayol
École Nationale Supérieure des Mines de Saint-Étienne
158 cours Fauriel
42023 Saint-Étienne Cedex 2
France
Tél:+33(0)4 77 42 83 36
Fax:+33(0)4 77 42 66 66
http://zimmer.aprilfoolsreview.com/
Received on Friday, 7 September 2012 10:41:58 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:25:51 GMT