W3C home > Mailing lists > Public > public-sparql-dev@w3.org > July to September 2006

RE: Difference operator in SPARQL

From: Seaborne, Andy <andy.seaborne@hp.com>
Date: Tue, 11 Jul 2006 16:30:43 +0100
Message-ID: <DF5E364A470421429AE6DC96979A4F6FB6A72B@sdcexc04.emea.cpqcorp.net>
To: "Andrew Newman" <andrewfnewman@gmail.com>, <public-sparql-dev@w3.org>


The ultimate reason is because no one asked for it!  The use case and
requirements process didn't identify it as a requirement and no
commenter or working group member made a proposal.

	Andy

-------- Original Message --------
> From: Andrew Newman <>
> Date: 9 July 2006 14:12
> 
> I'm currently searching for reasons why set difference may not have
> been included in SPARQL.  The places I have seen it mentioned all seem
> to suggest that SPARQL would be incomplete without it [1][2][3].  And
> another example works around it using FILTER [4].   
> 
> I'm looking into this as one of the ways OPTIONAL could have been
> implemented would've been a combination of project, join, difference
> and union (3 of which are supported in SPARQL directly).  
> 
> [1] http://www.hpl.hp.com/techreports/2005/HPL-2005-170.pdf
> [2] http://www.polleres.net/publications/poll-etal-2006b.pdf
> [3]
>
http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2005Mar/007
9.html
> [4] http://dblab.sogang.ac.kr/icde06/workshops/data/055_SWDB02.pdf 
Received on Tuesday, 11 July 2006 15:31:20 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 8 January 2008 14:17:05 GMT