- From: Axel Polleres <axel.polleres@deri.org>
- Date: Mon, 17 Oct 2011 22:21:41 +0200
- To: Andy Seaborne <andy.seaborne@epimorphics.com>
- Cc: <public-rdf-dawg@w3.org>
Updated with the link to http://www.w3.org/TR/sparql11-query/#modOrderBy as suggested. best, Axel On 17 Oct 2011, at 22:16, Andy Seaborne wrote: > > > On 17/10/11 20:19, Axel Polleres wrote: > > Andy, all, > > > > I have adapted the response draft for Jerven Bolleman (essentially incorporating your arguments), see > > http://www.w3.org/2009/sparql/wiki/CommentResponse:JBolleman-1 > > > > Please check especially the following (I wasn't 100% sure what you meant by > >> By the way, an "ORDER BY *" is still not a gauaranteed total ordering. > > but I guess it was in spirit this: > > -------- > > First of all, note that a shortcut like "ORDER BY *" as you suggest would not guarantee a predicable total order of results (for instance when blank nodes are returned, since two separate calls are not guaranteed to return the same blank node identifiers). > > -------- > > While its's true that bNodes don't sort predictably, there are more > important and significant cases though that would matter: > Why not refer to the text in: > > http://www.w3.org/TR/sparql11-query/#modOrderBy > > (which is SPARQL 1.0 text) > > Andy > > > > > I just see Jerven asking about the state of his comment (will answer him offlist that we're at it, but I'd appreciate feedback to get this oune out quickly > > > > > > thanks a lot, > > Axel > > > > > > On 17 May 2011, at 17:41, Andy Seaborne wrote: > > > >> > >> > >> On 17/05/11 13:40, Axel Polleres wrote: > >>> Hi all, > >>> > >>> drafted a response to > >>> > >>> http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2011May/0016.html > >>> http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2011May/0017.html > >>> > >>> at > >>> http://www.w3.org/2009/sparql/wiki/CommentResponse:JBolleman-1 > >>> > >>> please check/acknowledge > >>> > >>> thanks, > >>> Axel > >> > >> We did consider things in this area [1] and so we can say we actively > >> were aware of the issue and choose, on time resource issue grounds, not > >> to address the matter. (voting record?) > >> > >> [1] http://www.w3.org/2009/sparql/wiki/Feature:Cursors > >> > >> Let's at least say this is a protocol issue not a query issue. Existing > >> HTTP mechanisms are applicable like ETags for consistency and ranges for > >> slicing. Client side paging off a stream of results is also a candidate > >> mechanism. > >> > >> Cursors, paging, (transactions) etc are about controlling the flow of > >> results and about results over multiple requests, not in defining results. > >> > >> I think this clear-cut separation is important because it then can > >> address interactions with update, system restarts and anything that > >> means the server would loose state or simple re-execution of the query > >> would produce different answers even in a deterministic query processor. > >> > >> By the way, an "ORDER BY *" is still not a gauaranteed total ordering. > >> > >> Andy > >> > >> > > >
Received on Monday, 17 October 2011 20:22:22 UTC