- From: Axel Polleres <axel.polleres@deri.org>
- Date: Mon, 24 Nov 2008 15:46:23 +0000
- To: Chris Welty <cawelty@gmail.com>
- CC: Jos de Bruijn <debruijn@inf.unibz.it>, "Public-Rif-Wg (E-mail)" <public-rif-wg@w3.org>
Chris Welty wrote: > > Axel Polleres wrote: >>>> I was hoping we could get BLD a usable rules language for RDF, >>>> compatible with SPARQL. (And similar problems will arise if we >>>> pursue to >>>> suggest RIF to the RDB2RDF people: If we as a working group approach >>>> them and say: look at RIF, we should then not be in the position that, >>>> if they agree to do so, having to answer them: "BUT, BTW RIF doesn't >>>> work for that, you need to do your own dialect from scratch, your >>>> problem...") >>>> >>>> I see some very fundamental issues here. >>> >>> I would be very interested to see whether there are any features >>> required by RDB2RDF that are not provided by RIF. >> >> I have no concrete example as of now, but my rationale is: if we run >> into troubles with SPARQL, we might also run into troubles with SQL, >> since they share many underlying assumptions. > > If you're going to judge BLD by itself in terms of its suitability to > address the requirements of datatabase query language you will certainly > find it falls short. So don't set unreasonable expectations - BLD is > the *basic* *logic* dialect. I realize you know this, but when you say > "I was hoping we could get BLD a usable rules language for RDF, > compatible with SPARQL," it makes me think you've forgotten. > > The RIF approach to something like RDB2RDF would be to start with BLD > and then extend it to a dialect that supports the additional things they > need. And depending on how hard you stress "need" (as opposed to "want" > or "would find convenient") you will probably find the dialect is not a > big extension. I agree. BTW: An example of what they explicitly mentioned and which is not covered per se in RIF are aggregates. > [As an aside, I was just working with some DB folks last week here (on > something unrelated) and overheard the comment, "most experts know the > 2/3 of SQL to avoid". SPARQL also has its things to avoid.] > > -Chris > -- Dr. Axel Polleres Digital Enterprise Research Institute, National University of Ireland, Galway email: axel.polleres@deri.org url: http://www.polleres.net/
Received on Monday, 24 November 2008 15:47:08 UTC