Re: [Wikidata] "Implementing" OWL RL in SPARQL (Was: qwery.me - simpler queries for wikidata)
On 11/13/2015 01:21 AM, Markus Krötzsch wrote: > On 12.11.2015 22:09, Peter F. Patel-Schneider wrote: >> On 11/12/2015 09:10 AM, Markus Krötzsch wrote: >> [...] >>> On the other hand, it is entirely possible to implement correct OWL QL >>> (note: >>> *QL* not *RL*) reasoning in SPARQL without even using "rules" that need any >>> recursive evaluation [3]. This covers all of RDFS, and indeed some of the >>> patterns in these queries are quite well-known to Wikidata users too (e.g., >>> using "subclassOf*" in a query). Depending on how much of OWL QL you want to >>> support, the SPARQL queries you get in this case are more or less simple. >>> This >>> work also gives arguments as to why this style of SPARQL-based >>> implementation >>> does (most likely) not exist for OWL RL [3]. >> >> Does OWL QL cover *all* of RDFS, even things like subproperties of >> rdfs:subclassOf and rdfs:subPropertyOf? > > No, surely not. What I meant is the RDFS-fragment of OWL DL here (which is > probably what RDFS processors are most likely to implement, too). > > I think I recall you showing P-hardness of RDFS proper a while ago, which > would obviously preclude translation into single SPARQL 1.1 queries (unless > NL=P). Yes indeed, and hence my query. > > Markus > > peter ___ Wikidata mailing list Wikidata@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata
Re: [Wikidata] "Implementing" OWL RL in SPARQL (Was: qwery.me - simpler queries for wikidata)
On 11/12/2015 09:10 AM, Markus Krötzsch wrote: [...] > On the other hand, it is entirely possible to implement correct OWL QL (note: > *QL* not *RL*) reasoning in SPARQL without even using "rules" that need any > recursive evaluation [3]. This covers all of RDFS, and indeed some of the > patterns in these queries are quite well-known to Wikidata users too (e.g., > using "subclassOf*" in a query). Depending on how much of OWL QL you want to > support, the SPARQL queries you get in this case are more or less simple. This > work also gives arguments as to why this style of SPARQL-based implementation > does (most likely) not exist for OWL RL [3]. Does OWL QL cover *all* of RDFS, even things like subproperties of rdfs:subclassOf and rdfs:subPropertyOf? peter ___ Wikidata mailing list Wikidata@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata
Re: [Wikidata] "Implementing" OWL RL in SPARQL (Was: qwery.me - simpler queries for wikidata)
On 12.11.2015 22:09, Peter F. Patel-Schneider wrote: On 11/12/2015 09:10 AM, Markus Krötzsch wrote: [...] On the other hand, it is entirely possible to implement correct OWL QL (note: *QL* not *RL*) reasoning in SPARQL without even using "rules" that need any recursive evaluation [3]. This covers all of RDFS, and indeed some of the patterns in these queries are quite well-known to Wikidata users too (e.g., using "subclassOf*" in a query). Depending on how much of OWL QL you want to support, the SPARQL queries you get in this case are more or less simple. This work also gives arguments as to why this style of SPARQL-based implementation does (most likely) not exist for OWL RL [3]. Does OWL QL cover *all* of RDFS, even things like subproperties of rdfs:subclassOf and rdfs:subPropertyOf? No, surely not. What I meant is the RDFS-fragment of OWL DL here (which is probably what RDFS processors are most likely to implement, too). I think I recall you showing P-hardness of RDFS proper a while ago, which would obviously preclude translation into single SPARQL 1.1 queries (unless NL=P). Markus ___ Wikidata mailing list Wikidata@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata
Re: [Wikidata] "Implementing" OWL RL in SPARQL (Was: qwery.me - simpler queries for wikidata)
On 12/11/2015 17:10, Markus Krötzsch wrote: I write this not to praise or "bury" any technology, just to clarify some apparent misconceptions. (In particular, I completely agree with the fact that SPARQL is not that hard to grok, and that nicer interfaces and maybe further tutorial-style introductions would be useful.) There's a start at a practical introduction on-wiki at https://www.wikidata.org/wiki/Wikidata:SPARQL_query_service/queries to queries on the Wikidata SPARQL system. Everyone is very welcome to jump in and improve it ! (A wiki page isn't a proper wiki page until lots of people have made it their own). -- James, ___ Wikidata mailing list Wikidata@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata
