- From: Pascal Molli <pascal.molli@univ-nantes.fr>
- Date: Mon, 10 Sep 2018 16:35:22 +0200
- To: Kingsley Idehen <kidehen@openlinksw.com>
- Cc: public-lod@w3.org
- Message-ID: <CAPKVQuNmurkNbu+RrMwBBo0Y9SJ1rDygGY+RGqmdQ5vsafN_dg@mail.gmail.com>
Dear all, Thanks all for this nice discussion. Our key message is that it is possible to build a performant public LOD server that ensures stability, responsiveness and complete results for any SPARQL query. By using quotas, SPARQL endpoints ensure stability and responsiveness but sacrifice completeness. One approach to solve this problem is to decompose a query into a set of subqueries that terminate under quotas with complete results (Limit/Offset...). This approach raises a major issue: how to ensure that such decomposition exists for any query? This requires to evaluate the execution time of a query and the number of results on a server with an unknown load. Consequently, it seems impossible to me to build a server that ensures stability, responsiveness and completeness for any query following the W3C SPARQL protocol. As pointed out by Ruben, TPF and SaGE execute SPARQL query without following the W3C SPARQL protocol. By changing the server interface, they ensure stability, responsiveness and completeness of any query. Compared to TPF, SaGE reduces drastically data transfer and execution time thanks to BGP support on server side. Now if we compare SaGe and Virtuoso *without quotas*, we demonstrated that Virtuoso is not stable, and is outperformed by SaGe when the load is increasing. Any feedback is welcome. -- Pascal On Sun, 9 Sep 2018 at 23:49, Kingsley Idehen <kidehen@openlinksw.com> wrote: > On 9/9/18 4:20 PM, Hugh Glaser wrote: > > So I don't understand why you seem obsessed with the idea that these > researchers should give you access to use their resources, when what you > presumably want to do is repeat their experiments in your own environment > and control, so you can be confident off the results. > > > I never said or insinuated that. > > I just wanted them to clarify their key message, which is confusing for > a variety of reasons already outlined. > > > -- > Regards, > > Kingsley Idehen > Founder & CEO > OpenLink Software (Home Page: http://www.openlinksw.com) > > Weblogs (Blogs): > Legacy Blog: http://www.openlinksw.com/blog/~kidehen/ > Blogspot Blog: http://kidehen.blogspot.com > Medium Blog: https://medium.com/@kidehen > > Profile Pages: > Pinterest: https://www.pinterest.com/kidehen/ > Quora: https://www.quora.com/profile/Kingsley-Uyi-Idehen > Twitter: https://twitter.com/kidehen > Google+: https://plus.google.com/+KingsleyIdehen/about > LinkedIn: http://www.linkedin.com/in/kidehen > > Web Identities (WebID): > Personal: http://kingsley.idehen.net/public_home/kidehen/profile.ttl#i > : > http://id.myopenlink.net/DAV/home/KingsleyUyiIdehen/Public/kingsley.ttl#this > > > -- Pascal Molli <http://pagesperso.lina.univ-nantes.fr/~molli-p> Full Professor, Nantes University <http://www.univ-nantes.fr/> Head of GDD <https://sites.google.com/site/gddlina/>* team*, LS2N <http://ls2n.fr/>, UFR de Sciences et Techniques 2, rue de la Houssinière BP 92208 44322 NANTES CEDEX 3 Tel : +33 251125810 pascal.molli@univ-nantes.fr
Received on Monday, 10 September 2018 14:35:58 UTC