- From: Andy Seaborne <andy@apache.org>
- Date: Fri, 29 Jul 2016 16:02:44 +0100
- To: public-sparql-exists@w3.org
Peter wrote: > To get the maximum conformance to the SPARQL spec, yes, you have to do the > injection into every group graph pattern. I don't think that that is the > best way to go. However, it may be that this group shouldn't produce the best > solution but instead a worse solution that is closer to the spec. One way we can approach this is to describe the characteristics for a solution. That captures the ideal. There may be different ways to achieve that and some may be partial given where we are starting from. I agree that we may be better or necessary to make tradeoffs - we'll have to see as we go along. What is required is that the range of a valve is restricted by the values in the current row being FILTERed. One implementation is VALUES-at-every BGP (and other points variables get bound). Another is, for simple entailment, is to restrict the bindings by FILTER(sameTerm(?x, <value>) allowing for concrete blank nodes there (that is where substitution comes from when BGPs are solved by joins). That isn't intend to be an exclusive list I'm sure there are other ways to consider as well. Andy
Received on Friday, 29 July 2016 15:03:14 UTC