Hi What happens if you just remove the resource type triple pattern ? As rdf:type is very expensive due to its nature, as in RDF_QUAD table you are going to have many members (or participants) in the rdf:type relation that have to be evaluated whenever its used in a query, hence the overhead. Or rather than rdf:type which hits instantiation of all class instances, a query can simply negate this cost by focusing on a distinct selection of attributes in the query dataset which is then evaluated for solution production.
Best Regards Hugh Williams Professional Services OpenLink Software, Inc. // http://www.openlinksw.com/ Weblog -- http://www.openlinksw.com/blogs/ LinkedIn -- http://www.linkedin.com/company/openlink-software/ Twitter -- http://twitter.com/OpenLink Google+ -- http://plus.google.com/100570109519069333827/ Facebook -- http://www.facebook.com/OpenLinkSoftware Universal Data Access, Integration, and Management Technology Providers > On 7 Nov 2016, at 06:30, 손태모 <ths...@li-st.com> wrote: > > Dear all, > > i have some difficulty with text search in virtuoso using bif:contains > property. > > > if i specified graph name or resource type, the text search query runs > extremely slow ~~ > > but it runs very fast if i remove graph CLAUSE and resource type triple > pattern , > > > the two queries are shown bellow. > > -- extremely slow query > > PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> > PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> > PREFIX bif: <bif:> > SELECT * > FROM <http://lod.knps.or.kr/knps> > WHERE { ?s rdfs:label ?label . ?label bif:contains "'덕유산'" . > ?s rdf:type <http://lod.knps.or.kr/schema/class/NationalPark> .} > LIMIT 5 > OFFSET 0 > > > > -- extremely fast query > > PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> > PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> > PREFIX bif: <bif:> > SELECT * > WHERE { ?s rdfs:label ?label . ?label bif:contains "'지리산'" .} > > > i suppose that if i specified the graph name and type of resource using > "rdf:type" , the query must run much faster than non-specified query in > common sense, am i right? but the query above shows just inverse result > about this issue. > > My question is : > > 1. what is the reason cause the problem above? > 2. if i want to run text search using type and graph specified query, > then how can i make it ? > > > thanks . > > > Best Regards > > > > > -- > ================================ > Sohn, Taemo > LiST Co., Ltd. > 9th Floor, Yangyong bldg., > 3, Beodeunaru-ro 19-gil, Yeongdeungpo-gu, Seoul, Korea > > Tel +82 2 2632 5133 > Fax +82 2 2632 5134 > Mobile +82 10 2647 0108 > ================================ > > > ------------------------------------------------------------------------------ > Developer Access Program for Intel Xeon Phi Processors > Access to Intel Xeon Phi processor-based developer platforms. > With one year of Intel Parallel Studio XE. > Training and support from Colfax. > Order your platform today. http://sdm.link/xeonphi > _______________________________________________ > Virtuoso-users mailing list > Virtuoso-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/virtuoso-users
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