- From: Leigh Dodds <leigh.dodds@talis.com>
- Date: Sat, 24 Oct 2009 14:09:18 +0100
- To: public-rdf-dawg-comments@w3.org
Hi, Here are some personal comments/questions on the 22/10/2009 WD of SPARQL 1.1. * Example in Section 2. I don't think the project expression conforms with grammar shown latter in the doc; missing brackets? I know this is still up for discussion, but thought I'd point it out * Section 2, Syntax. re: the note about using FILTER instead of HAVING. Assuming I'm reading the comment correctly, I think for readability purposes its better to have a separate keyword (HAVING) rather than re-use the FILTER keyword. I think its clearer that there are different constraints (i.e. aggregates allowed or not) on the expression, and retains similarity with SQL. * Section 3. Text above example query is wrong, I think it should ready "from all the people that Alice knows", not "that know Alice". * Section 4. What is the rationale for including both a FILTER and a graph pattern operator for EXISTS/NOT EXISTS? If there are benefits in terms of expressivity or ease of implementation it would be good to be able to call these out in the specification. * Section 4. The NOT EXISTS and EXISTS graph pattern operators are described as "applying only to variables defined earlier in the pattern". What does "earlier" mean if a SPARQL processor can re-order the statements for optimization purposes? Does use of those operators have some impact on an implementations ability to do that? Cheers, L. -- Leigh Dodds Programme Manager, Talis Platform Talis leigh.dodds@talis.com http://www.talis.com
Received on Saturday, 24 October 2009 13:17:50 UTC