- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Tue, 11 Jul 2006 16:30:43 +0100
- 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 UTC