Hi Kingsley, The idea is that our concept model I map to with R2RML is not the same as source tables. So just using output from Generate RDF Views would not work. I write custom R2RML code which maps from flat DB model to graph concept model
For example: Let it be the following tables: 1. Goods a. ID Integer b. Name String c. Category String d. SubCategory String 2. Customer a. ID Integer b. Name String 3. Order a. ID Integer b. Goods ID Integer c. Customer ID Integer These three tables map to our Concept model which is a bit different from table structure and I'm executing SPARQL Query like this: PREFIX: sq:<http://our_schema> SELECT * FROM <http://this_is_the_graph_name <http://this_is_the_graph_name%20> > WHERE { ?customer sq:hasOrder ?order . ?order sq:hasGoods ?goods . ?goods sq:Name ?goodsName . FILTER (?goodsName in ('Name1', 'Name2')) . ?goods sq:hasSubCategory ?subCategory . #note that subcategory is IRI ?subCategory a sq:SubCategory . ?subCategory sq:hasParentCategory ?category #note that category is IRI ?subCategory a sq:Category . }; In my particular case I map data from ~10 views to ~13 classes in our concept model and WHERE statement is a bit longer. Best regards, Alexander Efimov. From: Kingsley Idehen [mailto:kide...@openlinksw.com] Sent: Monday, December 14, 2015 6:46 PM To: Efimov, Alexander <alexander.efi...@arcadia.spb.ru>; virtuoso-users@lists.sourceforge.net Cc: Gedich, Andrey <andrey.ged...@arcadia.spb.ru>; wced...@its.jnj.com Subject: Re: [Virtuoso-users] Find out which SQL query is generated from my SPARQL On 12/14/15 9:21 AM, Efimov, Alexander wrote: Hi, I've built R2RML mappings, but my SPARQL Query (I expect that to be joining across about 10 views in DB) runs for hours. Is there a way to get a SQL query which Virtuoso generates and runs over the database views? I have tried to use trace_on(); command but have nothing human readable in terms of SQL queries executed. Thanks. Efimov, I don't quite understand what you are doing, but I would suggest you tried the following: 1) Make a SQL view from you 10 table query -- have a sense of the performance of this view 2) Use the Virtuoso RDF Views Wizard to generate RDF Views script (this includes R2RML generation) 3) Choose the option to make materialized RDF Views (i.e., to actually generate physical rather than virtual triples in the quad store that are syn'cd with source) 4) Re-test outcome and provide feedback about performance . Kingsley ------------------------------------------------------------------------------ _______________________________________________ Virtuoso-users mailing list Virtuoso-users@lists.sourceforge.net<mailto:Virtuoso-users@lists.sourceforge.net> https://lists.sourceforge.net/lists/listinfo/virtuoso-users -- Regards, Kingsley Idehen Founder & CEO OpenLink Software Company Web: http://www.openlinksw.com Personal Weblog 1: http://kidehen.blogspot.com Personal Weblog 2: http://www.openlinksw.com/blog/~kidehen Twitter Profile: https://twitter.com/kidehen Google+ Profile: https://plus.google.com/+KingsleyIdehen/about LinkedIn Profile: http://www.linkedin.com/in/kidehen Personal WebID: http://kingsley.idehen.net/dataspace/person/kidehen#this
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