Hi Miguel, I can understand it's very useful if we can integrate some rules into SPARQL, i.e., enrich inference ability in SPARQL (that's SPIN). But integrate SPARQL into Jena rules is unclear, That's my understanding.
Best. On Sun, Mar 9, 2014 at 6:51 PM, Miguel Bento Alves <[email protected]>wrote: > Hi Cong, > > In introduction of the paper that you referred [2]: > "Still, SQL is often viewed to be more powerful in several respects² (I > think that this idea is also valid for SPARQL in the context) > "On the other hand, aggregates ... are missing in pure Datalog". > > Related to this point "increase the expressiveness of Jena², I think that > is very useful when you can represent your knowledge either through rules > or through SPARQL and commands. Read about the motivations of spin rules > [3][4]. > > [3] http://www.w3.org/Submission/2011/SUBM-spin-overview-20110222/ > [4] http://www.w3.org/Submission/2011/SUBM-spin-sparql-20110222/ > > Miguel > > > > On 09/03/14 22:24, "Cong Wang" <[email protected]> wrote: > > >Hi everybody, > > > >My name is Cong Wang, currently a Ph.D student at Wright State University > >with Pascal Hitzler. I am very interested two ideas, "Generate JSON from > >SPARQL directly" and "Define SPARQL commands in Jena rules". I have > >several > >questions regarding the two topics. > > > >For "Generate JSON from SPARQL directly", > > > >Is that you want translate sparql query into json format, such that we can > >use it to query json data? Since under W3C recommendation, there's way to > >translate sparql results into json [1]. The only missing part is > >converting > >sparql query with json query. But even if so, I'm still not sure the > >significance. What's the motivation here? > > > >For "Define SPARQL commands in Jena rules", > > > >I remember there's a paper by Axel Polleres [2]. It's about translating > >SPARQL into datalog. Although datalog is arbitrary variables and Jena > >rules > >is only 3 variables, there should be a way to convert. > > > >But I don't quite understand how it can "increase the expressiveness of > >Jena". In principle, SPARQL is just indexing, and Jena rules actually have > >already indexed the triples while grounding variables. > > > >[1]. http://www.w3.org/TR/sparql11-results-json/ > >[2]. Axel Polleres: From SPARQL to rules (and back). WWW 2007 > > > > > >Best regards. > > > >-- > >Cong Wang > >Ph.D Candidate, > >Kno.e.sis Center, > >Wright State University. > > > -- Cong Wang Ph.D Candidate, Kno.e.sis Center, Wright State University.
