(same question as yesterday) A few problems:
1/ Talis are turning off their online service so http://api.talis.com/... will stop working sometime. If this is a paid-for store, that wil be in several months; if hosted for free, it'll happen in the next few days.
2/ The services have a 30s timeout - if that goes off, you get no results from the SERVICE.
3/ DBpedia has 4/ You can use a subselect to restrict the remote query part: SERVICE <...> { SELECT * { ... } LIMIT 300 } 4/ Execution is bottom up: The second block: SERVICE <http://dbpedia.org/sparql> { ?thCenturyClassicalComposers0 rdf:comments ?comment } may be executed repeatedly due to the execution strategty of ARQ but when I try: PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> SELECT * { ?thCenturyClassicalComposers0 rdfs:comments ?comment } at the DBpedia sparql endpoint I get: Error HTTP/1.1 509 Bandwidth Limit Exceeded Andy On 31/07/12 08:40, Olivier Rossel wrote:
Hi all. I would like to try Jena basic federation. I tried this query: SELECT DISTINCT ?thCenturyClassicalComposers0 WHERE { SERVICE <http://api.talis.com/stores/bbc-backstage/services/sparql> { ?thCenturyClassicalComposers0 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/class/yago/20thCenturyClassicalComposers> . }} LIMIT 300 with the code provided here: cf http://tech.groups.yahoo.com/group/jena-dev/message/48130 I get some results. Now I try this query: SELECT DISTINCT ?thCenturyClassicalComposers0 ?comment WHERE { SERVICE <http://api.talis.com/stores/bbc-backstage/services/sparql> {?thCenturyClassicalComposers0 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/class/yago/20thCenturyClassicalComposers> . } SERVICE <http://dbpedia.org/sparql> {?thCenturyClassicalComposers0 <http://www.w3.org/2000/01/rdf-schema#comment> ?comment} } LIMIT 300 I get no result. But when checking data on each endpoint, I should get some results. Is there something wrong in my SPARQL SERVICE syntax? BTW, being able to limit/offset/orderBy and OPTIONALize each SERVICE block would be uber nice ! ! ! Is it possible already?