Re: Subjects as Literals, [was Re: The Ordered List Ontology]

On Fri, 2010-07-02 at 12:42 +0200, Richard Cyganiak wrote:
> Hi Yves,

> On 2 Jul 2010, at 11:15, Yves Raimond wrote:
> > I am not arguing for each vendor to implement that. I am arguing for
> > removing this arbitrary limitation from the RDF spec. Also marked as
> > an issue since 2000:
> > http://www.w3.org/2000/03/rdf-tracking/#rdfms-literalsubjects
> 
> The demand that W3C modify the specs to allow literals as subjects  
> should be rejected on a simple principle: Those who demand that  
> change, including yourself, have failed to put their money where their  
> mouth is. Where is the alternative specification that documents the  
> syntactic and semantic extension? Where are the proposed "RDF/XML++"  
> and "RDFa++" that support literals as subjects? Where are the patches  
> to Jena, Sesame, Redland and ARC2 that support these changes?

+1, with a small correction. I'd expect a patch for Virtuoso as well ;)

Actually, the approval of a new spec will require two adequate
implementations. I can't imagine that existing vendors will decide to
waste their time to make their products worse in terms of speed and disk
footprint and scalability. "The most efficient critics is sabotage", you
know.

Some new vendor may of course try to become a "strikebreaker" but his
benchmark runs will look quite poorly, because others will continue to
optimize any SPARQL BGP like

?s ?p ?o .
?o ?p2 ?s2 .

into more selective

?s ?p ?o . FILTER (isREFERENCE (?o)) .
?o ?p2 ?s2 .

and this sort of rewriting will easily bring them two orders of
magnitude of speed on a simple query with less than 10 triple patterns.
Keeping in mind that Bio2RDF people tend to write queries with 20-30
triple patterns mostly connected into long chains, the speed difference
on real life queries will be a blocking issue.

-----

The discussion is quite long; I'm sorry I can't continue to track it
accurately, I'm on a critical path of a new Virtuoso release.

If somebody is interested in
a whole list of reasons why I will not put this feature into the DB core
or
a whole list of workarounds for it at DB application level
or
a detailed history of round Earth and Columbus
then
ping me and I'll write a page at ESW wiki.

Best Regards,

Ivan Mikhailov
OpenLink Virtuoso
http://virtuoso.openlinksw.com

Received on Friday, 2 July 2010 12:39:44 UTC