- From: Andy Seaborne <andy.seaborne@epimorphics.com>
- Date: Mon, 17 Oct 2011 21:16:01 +0100
- To: Axel Polleres <axel.polleres@deri.org>
- CC: public-rdf-dawg@w3.org
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 20:16:33 UTC