On 4/16/13 5:47 PM, Luca Matteis wrote:
Kingsley, this is exactly my problem with SPARQL. So much jargon and complexity. Cursors? Scrollable engine? Column-storage? Vectorized execution?
So you've gotta have the same jargon problem with SQL and RDBMS technology too. Why are you singling out SPARQL? Those items are old news in the RDBMS realm.
Web service REST APIs are usually located on top of SQL interfaces for this very reason! Because SQL is too complex to be exposed as a service to users!
SQL isn't too complex. It is too limited for the stuff that RDF makes possible :-)
Kingsley
On Tue, Apr 16, 2013 at 11:38 PM, Kingsley Idehen <[email protected] <mailto:[email protected]>> wrote:On 4/16/13 5:22 PM, Aidan Hogan wrote: On 16/04/2013 22:05, Kingsley Idehen wrote: On 4/16/13 4:15 PM, Aidan Hogan wrote: The ability to answer "I don't know" or "cannot compute right now" or "I need more time" would make anything trivially scalable. But "I don't know" or "cannot compute" or "I need more time" is not a valid SPARQL answer. Nor is stopping after the first X answers are returned. Let's have a constructive conversation via SPARQL protocol URLs. I thought my comments were constructive? (If not, I'd be happy to hear why not.) Anyways, as per my previous reply ... With respect to this SPARQL query service: http://lod.openlinksw.com/sparql I would like a response complaint with the SPARQL standard for either of the following two SPARQL queries: SELECT * WHERE {?s foaf:knows ?o} or SELECT * WHERE {?s foaf:knows ?o . ?o foaf:knows ?o2 .} Cheers, Aidan Did you perform a count on either? If so, why no LIMIT in the query ? If you want no LIMIT into what bucket are you placing the result? Would you dare send the following to a decently sized RDBMS and use it as the basis for assessing scale: SELECT * FROM TABLE_X Anyway, re. my comments above, SPARQL Protocol URLs: 1. http://lod.openlinksw.com/c/GNC4S3R -- query result re. count 2. http://lod.openlinksw.com/c/GSNV76O -- query definition re. the above. So what do you do when the result set exceeds the capacity of the bucket? You make a scrollable cursor (the types vary: snapshot, keyset, dynamic, or mixed model) and then page through the data. Alternatively, you make a multi-dimensional view (known as facets in the RDF / Semantic Web UI world) and you leverage the entity relationship semantics as the basis for a scrollable cursor. The paragraph above describes what's happening at: http://lod.openinksw.com/fct -- its a scrollable cursor engine, something that's quite common in the RDBMS realm, but they lack relation semantics of RDF. Same thing applies to column-storage, key compression, and vectorized execution which are also reapplications of RDBMS realm technology in new RDF context so that we have the best of both worlds.--Regards, Kingsley Idehen Founder & CEO OpenLink Software Company Web: http://www.openlinksw.com Personal Weblog: http://www.openlinksw.com/blog/~kidehen <http://www.openlinksw.com/blog/%7Ekidehen> Twitter/Identi.ca handle: @kidehen Google+ Profile: https://plus.google.com/112399767740508618350/about LinkedIn Profile: http://www.linkedin.com/in/kidehen
-- Regards, Kingsley Idehen Founder & CEO OpenLink Software Company Web: http://www.openlinksw.com Personal Weblog: http://www.openlinksw.com/blog/~kidehen Twitter/Identi.ca handle: @kidehen Google+ Profile: https://plus.google.com/112399767740508618350/about LinkedIn Profile: http://www.linkedin.com/in/kidehen
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