Dear all; We've come across an issue with our server hosting company being unable to start Virtuoso on the due to the upgrade they put in place to address the Heartbleed bug issue, which removed libssl.so.6 that is required by Virtuoso.
Then, we rebuilt Virtuoso[0], from running ./configure on wards to expect that ultimately this will relink virtuoso-t against the newer version of OpenSSL on the system. However, we got the following error message: /opt/virtuoso/bin/virtuoso-t: error while loading shared libraries: libssl.so.6: cannot open shared object file: No such file or directory Do you have anyone who has the same problem as mine? If so, then could you give me a small tip for it? Best, Soonho -----Original Message----- From: Bart Vandewoestyne [mailto:bart.vandewoest...@telenet.be] Sent: Friday, April 04, 2014 7:20 AM To: virtuoso-users@lists.sourceforge.net Subject: Re: [Virtuoso-users] speeding up a query On 2014-04-03 15:00, Kingsley Idehen wrote: > On 4/3/14 7:47 AM, Bart Vandewoestyne wrote: >> Hello list, >> >> INITIAL REMARK: if this is not the appropriate mailing list for this >> question, please let me know the best place to ask questions >> regarding SPARQL queries and their optimization. >> >> I'm a beginner when it comes to writing SPARQL queries. I am trying >> to speed up a certain query that I got from someone, which has the >> following form: >> >> SELECT ?val (COUNT(DISTINCT ?id) as ?vc) WHERE { >> ?id<http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?val. >> ?id ?property ?property_value. >> ?property_value bif:contains "'foo'". >> ?id ?property1 ?property_value1. >> ?property_value1 bif:contains "'bar'". >> } >> GROUP BY ?val >> ORDER BY DESC(?vc) >> >> >> First of all, I noticed that I can write it more elegantly as follows: >> >> SELECT ?val (COUNT(DISTINCT ?id) as ?vc) WHERE { >> ?id<http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?val ; >> ?property1 ?property_value1 ; >> ?property2 ?property_value2 . >> >> ?property_value1 bif:contains "'foo'" . >> >> ?property_value2 bif:contains "'bar'" . >> } >> GROUP BY ?val >> ORDER BY DESC(?vc) >> >> Secondly, looking at >> http://docs.openlinksw.com/virtuoso/queryingftcols.html my educated >> guess was that I could replace this query with >> >> SELECT ?val (COUNT(DISTINCT ?id) as ?vc) WHERE { >> ?id<http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?val ; >> ?property ?property_value . >> ?property_value bif:contains 'foo or bar' . >> } >> GROUP BY ?val >> ORDER BY DESC(?vc) >> >> and my hope was that this version would run a little faster (don't >> ask me why... just a wild guess that I would try) >> >> Unfortunately, this last version seems to give different query results. >> >> My two questions: >> >> 1) Why is this last query giving different results? Am I >> misinterpreting something? >> >> 2) Is there a way I can rewrite the original query so that it runs >> faster? >> >> Thanks! >> Bart > > One little issue here is that you don't indicate the role of named > graphs i.e., do you want this query to be scoped to every named graph > or to specific named graphs? As you can imagine, this has impact on > the perceived performance. > > You could use the public LOD Cloud instance to demonstrate your quest, > and share a SPARQL query results URL for accelerated analysis (on our > side). > > [1] http://lod.openlinksw.com/sparql -- LOD Cloud Cache Instance (50 > Billion+ Triples) Hello Kingsley, I'm afraid I'm still too new to SPARQL to completely understand your answer... I'm not really familiar with named graphs yet, but after some googling around, i think I can conclude that I'm not using any named graphs for two reasons: 1) My SPARQL queries are as written above, not using a FROM NAMED or GRAPH keyword. 2) I seem to have no named graphs in my triple store, as demonstrated by the following query: SQL> sparql select distinct ?g where { graph ?g {?s ?p ?o} }; g LONG VARCHAR _______________________________________________________________________________ 0 Rows. -- 1 msec. So my two questions remain: 1) Why is the rewritten query SELECT ?val (COUNT(DISTINCT ?id) as ?vc) WHERE { ?id<http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?val ; ?property ?property_value . ?property_value bif:contains 'foo or bar' . } GROUP BY ?val ORDER BY DESC(?vc) giving me different results than the original one: SELECT ?val (COUNT(DISTINCT ?id) as ?vc) WHERE { ?id<http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?val. ?id ?property ?property_value. ?property_value bif:contains "'foo'". ?id ?property1 ?property_value1. ?property_value1 bif:contains "'bar'". } GROUP BY ?val ORDER BY DESC(?vc) 2) Is there a way to rewrite the original query so that it runs faster? Or can I apply other tricks? For as far as I understand from the Virtuoso docs, I cannot use any indexing tricks to speed this query up because the default indexing scheme on RDF_QUAD is already active and should suffice? If you need further information, feel free to ask. Kind regards, Bart ------------------------------------------------------------------------------ _______________________________________________ Virtuoso-users mailing list Virtuoso-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/virtuoso-users ------------------------------------------------------------------------------ Is your legacy SCM system holding you back? Join Perforce May 7 to find out: • 3 signs your SCM is hindering your productivity • Requirements for releasing software faster • Expert tips and advice for migrating your SCM now http://p.sf.net/sfu/perforce _______________________________________________ Virtuoso-users mailing list Virtuoso-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/virtuoso-users
