- From: Graham Klyne <graham.klyne@zoo.ox.ac.uk>
- Date: Wed, 18 May 2011 08:19:46 +0100
- To: Steve Harris <steve.harris@garlik.com>
- CC: public-rdf-dawg-comments@w3.org
For the purposes of your formal process, please treat this as acknowledgement of satisfactory resolution. ... Issue 2 is certainly resolved. For issue 1, I think the test cases probably help out, but they're not so easy to navigate for casual enquiry. Is there a human-readable version of the test case manifest? It seems much of the data is there from which one could be generated automatically. #g -- Steve Harris wrote: > In response to http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2010Sep/0000.html > > > 1. Editorial > > > > I'm finding the section on aggregates is quite hard to follow. > > > > More examples, especially for GROUP_CONCAT, might make it easier > > to understand the link between the algebra and its practical consequences > > in SPARQL queries. > > There is a balance between providing examples, and making the document too long. > > The explanatory section on aggregates has been expanded, and there are now some testcases for aggregates http://www.w3.org/2009/sparql/docs/tests/data-sparql11/aggregates/ - which hopefully illustrate the behaviour. > > > Also, I can't find any indication of the interaction between GROUP BY and ORDER > > BY, where the ORDER BY specifies a variable not named in the GROUP BY: is this > > allowed? If so, what effect does it have (e.g. on GROUP_CONCAT)? > > Aggregate operations are performed on a multiset, so order is not preserved. > > The group discussed the possibility of adding this feature but decided to postpone it to a future working group. > > Please note: “ORDER BY after a GROUP BY must only use variables exposed by the GROUP. Use of non-grouping variable outside the GROUP BY is not legal and a required syntax error.” > > For example: > > SELECT ?book ?title > WHERE { > ?book dc:title ?title } > GROUP BY ?book > ORDER BY ?title > ==> error. > > > 2. A Nice-to-have feature > > We understand that you have now seen another solution to this issue, see http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2010Oct/0001.html. > > Could you please respond to this message saying whether this comment has been answered to your satisfaction. > > Regards, > Steve, on behalf of the SPARQL Working Group >
Received on Wednesday, 18 May 2011 10:59:27 UTC