triplestore

Open Source Triple store for OWL [closed]

由 主宰稳场 提交于 2019-12-21 06:08:36
问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 2 years ago . I'm new with triple stores and I need a good recommendation for an open source triple store, where I can store OWL files. Does someone have some recommendations for me? Thank you a lot! Bests M 回答1: I think 4Store would be a good choice, which is fast and stable. You can get some information from project

Duplicate triple in RDF, authoritative view?

由 此生再无相见时 提交于 2019-12-12 09:49:43
问题 if a triple store contains twice the same triple, what is (if any exist) the authoritative position about this redundancy ? Additionally, should a triplestore be allowed to store twice the same triple within the same context ? I ask this because in rdflib apparently you can store the same triple twice (or more). This is the reader import rdflib from rdflib import store s = rdflib.plugin.get('MySQL', store.Store)('rdfstore') config_string = "host=localhost,password=foo,user=foo,db=foo" rt = s

Federated query with secured SPARQL endpoint

由 南笙酒味 提交于 2019-12-11 02:04:58
问题 I'm trying to use federated queries with Jena via a Fuseki endpoint. With the SERVICE keyword in my SPARQL query, I'm connecting to a Stardog endpoint. As it's a secured URL, the endpoint is specified as follows: http://admin:admin@url. As this is not secure, Jena shows the following message: Code: 36/HAS_PASSWORD in USER: Including passwords in URIs is deprecated. According to the docs, you can specify srv:queryAuthUser and srv:queryAuthPwd for the credentials. Is there any way to do this

Open world assumption and SPARQL in triple stores

由 六眼飞鱼酱① 提交于 2019-12-08 20:56:30
I would like to know if SPARQL, by default, adopts the open world assumption or if this depends on the triple stores that execute the SPARQL queries. And what are the implications of this assumption in queries. Best regards. Well.... I wonder whether this is really a good question for this site. I think not, but I'm gonna throw a few cents into the bucket anyway. To start with -- does it matter whether SPARQL "adopts" (and what does that mean, to you?) OWA, and, if so, why? Then, to address @AKSW's comment -- W3 differs with @AKSW's assertion, in at least the RDF 1.0 Spec (granted, that has

Error when I load RDF triples in TDB Triple Store

由 杀马特。学长 韩版系。学妹 提交于 2019-12-08 14:48:49
问题 I have a question for you: I have loaded my file RDF in TDB Triple Store: Dataset dataset = TDBFactory.createDataset(directory); Model model = dataset.getNamedModel("http://nameFile"); TDBLoader.loadModel(model, file ); Now, I would like to realize a procedure which checks whether the graph is on the Triple Store or not. I have written this code: String queryStr = "select * {graph <http://nameFile> { ?s ?p ?o }}"; Dataset dataset = TDBFactory.createDataset(directory); Query query =

Open world assumption and SPARQL in triple stores

由 旧时模样 提交于 2019-12-08 06:01:21
问题 I would like to know if SPARQL, by default, adopts the open world assumption or if this depends on the triple stores that execute the SPARQL queries. And what are the implications of this assumption in queries. Best regards. 回答1: Well.... I wonder whether this is really a good question for this site. I think not, but I'm gonna throw a few cents into the bucket anyway. To start with -- does it matter whether SPARQL "adopts" (and what does that mean, to you?) OWA, and, if so, why? Then, to

Filter by language only if the object is a literal

由 丶灬走出姿态 提交于 2019-12-06 01:51:38
问题 I've written the following query: SELECT DISTINCT ?predicate ?object ?label WHERE { VALUES ?subject { <http://dbpedia.org/resource/Hercules_(1997_film)> } ?subject ?predicate ?object . ?predicate rdfs:label ?label . FILTER(langMatches(lang(?object), "EN")) } LIMIT 100 When I write the FILTER line this way, I've essentially filtered out all non-literals ( side question: are literals the only type that can have a language tag? ) So, how do I keep all of my results and filter out non-english

Duplicate triple in RDF, authoritative view?

由 五迷三道 提交于 2019-12-05 20:29:26
if a triple store contains twice the same triple, what is (if any exist) the authoritative position about this redundancy ? Additionally, should a triplestore be allowed to store twice the same triple within the same context ? I ask this because in rdflib apparently you can store the same triple twice (or more). This is the reader import rdflib from rdflib import store s = rdflib.plugin.get('MySQL', store.Store)('rdfstore') config_string = "host=localhost,password=foo,user=foo,db=foo" rt = s.open(config_string,create=False) if rt != store.VALID_STORE: s.open(config_string,create=True) graph =

SPARQL 1.1 entailment regimes and query with FROM clause

由 倾然丶 夕夏残阳落幕 提交于 2019-12-05 18:44:52
I'm currently documenting/testing about SPARQL 1.1 entailment regimes and the recommendation repeatedly states that The scoping graph is graph-equivalent to the active graph but it does not specifies what is the active graph referring to : is it the data-set used in the query ? a union of all graphs in the store ? As a test to determine this , I got this graph URIed <http://www.example.org/> in a Sesame Memory store with RDF Schema and direct type inferencing store (v2.7.14) @prefix ex:<http://www.example.org/> . ex:book1 rdf:type ex:Publication . ex:book2 rdf:type ex:Article . ex:Article rdfs

Converting a SQLite Database to a triple store

由 流过昼夜 提交于 2019-12-05 18:32:17
Can somebody please describe the steps neccessary to convert a SQLite Database to a triple store? Is there a tool that can accomplish the task? This is a more complicated question then it seemed when I asked it, but the simple answer is that you normalize your database completely. After it is completely normalized each table stands for a predicate, one columns values represent the subject and one columns values represent the object. You can convert an arbitrary sql database to a triplestore on this basis. The function transform to triple convert any kind of relational data into triple format:
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