- From: Rob Shearer <Rob.Shearer@networkinference.com>
- Date: Thu, 6 May 2004 12:39:23 -0700
- To: "Seaborne, Andy" <andy.seaborne@hp.com>, "RDF Data Access Working Group" <public-rdf-dawg@w3.org>
I'm afraid I can't really support this as a requirement, although I think features which allow this result (albeit not necessary directly) would almost certainly be extremely useful. The thing is, "optional bindings" are really nothing more than unions between independent queries: union the results of the query with the binding with the results of the query without it. I'd say a more general-purpose "union" operator is quite a bit more important than this one particular form, and even then I'm not sure whether it rises to the level of requirement. > -----Original Message----- > From: public-rdf-dawg-request@w3.org > [mailto:public-rdf-dawg-request@w3.org] On Behalf Of Seaborne, Andy > Sent: 06 May 2004 08:40 > To: RDF Data Access Working Group > Subject: Requirement 3.6: Optional Match > > > > I suggest what I think are small changes: > > + including the term "graph pattern" as is in the suggested > text for 3.1. > + tweaking the title > + Be neutral to "optional triples" and "may-bind" variables. > > ------------------------ > > 3.6 Optional Matching > > It must be possible to express a query graph pattern that > does not fail to > match when some nominated part of the graph pattern fails to > match. Any > such triples matched by this optional part, or variable > bindings caused by > this optional part, can be requested in the results. > > ------------------------ > > Andy > > > > > For reference, the text in v1.39 is: > """ > 3.6 Optional Match > It must be possible to express a query that does not fail when some > nominated part of the query specifying "optional triples" > fails to match. > Any such triples matched by this optional part, or variable > bindings caused > by this optional part, can be returned in the results, if requested. > """ > >
Received on Thursday, 6 May 2004 15:41:53 UTC