Hi Bart, On 26-Aug-14 4:32 PM, Bart Vandewoestyne wrote:
On 2014-07-16 10:34, Alexey Zakhlestin wrote:On 14 Jul 2014, at 17:37, Bart Vandewoestyne <bart.vandewoest...@telenet.be> wrote:Our problem is the following: we observed that certain of our SPARQL queries have subqueries (that return IDs) that run rather slow (because of a slow bif:contains full-text-search). We therefore 'migrated'/'copied'/'flattened' some of our data to another technology/database/store that allows for faster textual search. Querying this database results in a list of IDs, and these IDs are then 'injected' in a SPARQL query (we simply create a SPARQL query string with all these IDs in the FILTER command). Apparently, we are limited to filtering 4094 IDs and I don't see a way to overcome this if the subquery returns more. Could there be a way to work-around this limitation at SPARQL level?Couple of untested thoughts: 1. try to use several IN() filters by joining them using OR FILTER(?id IN(1,2,3) or ?id IN(4,5,6)) 2. use UNION to join result sets { … . FILTER(?id IN(1,2,3) } UNION { … . FILTER(?id IN(4,5,6) }Getting back to my old question, I have another question :-) Am I right if I say that using an expression like ?id IN(1,2,3) is a Virtuoso-specific extension to the SPARQL standard?
It is indeed part of the SPARQL 1.1 Specification: -- http://www.w3.org/TR/sparql11-query/#func-in
Best Regards, Rumi Kocis
I can't seem to find anything about IN() online at http://www.w3.org/TR/rdf-sparql-query/#grammar nor http://www.w3.org/TR/sparql11-overview/ but if my interpretation of the grammar online at http://docs.openlinksw.com/virtuoso/rdfsparql.html is correct, then according to rule [47] the use of IN() is a Virtuoso-specific extension. Can anybody confirm? And if this is indeed a Virtuoso-specific extension, then what would be the most appropriate/efficient way to rewrite a FILTER-statement of the form FILTER (?id IN (1, 2, 3)) in a standard-conforming way? Kind regards, Bart ------------------------------------------------------------------------------ Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ _______________________________________________ Virtuoso-users mailing list Virtuoso-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/virtuoso-users
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