triplestore

问题 I am trying to build a 6-tuple store on top of wiredtiger. The tuples can be described as follow: (graph, subject, predicate, object, alive, transaction) Every tuple stored in the database is unique. Queries are like regular SPARQL queries except that the database store 6 tuples. Zero of more elements of a tuple can be variable. Here is an example query that allows to retrieve all changes introduces by a particular transaction P4X432 : SELECT ?graph ?subject ?predicate ?object ?alive WHERE {

问题 I am playing with Blazegraph. I insert some triples representing 'events', each of 'event' contains 3 triples and looks like this: <%event-iri%> <http://predicates/timestamp> '2020-01-02T03:04:05.000Z'^^xsd:dateTime . <%event-iri%> <http://predicates/a> %RANDOM_UUID% . <%event-iri%> <http://predicates/b> %RANDOM_UUID% . Timestamps represent consecutive moments of time, each next event is 1 minute later than the previous one. I made two sets of tests: once having 1 million events (so 3 million

问题 It seemed a trivial matter at the beginning but so far I have not managed to get the unique identifier for a given resource using SPARQL. What I mean is given, e.g., rdf:Description rdf:about="http://..." and then some properties identifying this resource, what I want to do is to first find this very resource and then retrieve all the triples given some URI. I have tried naïve approaches by writing statements in a WHERE clause such as: ?x rdf:about ?y and ?x rdfs:about ?y I hope I am being

问题 I have some triples that look like this: test:thing rdfs:label "Non-Language Label" test:thing rdfs:label "English Label"@en test:thing rdfs:label "French Label"@fr I'd like to form a sparql query that gives me the "Non-Language Label" AND the "French Label", if any exists. I tried this and it's not working: PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> SELECT ?label ?preferredLabel WHERE { test:thing rdfs:label ?label OPTIONAL { test:thing rdfs:label ?preferredLabel . FILTER (regex

问题 I have a knowledge base in Virtuoso. I know we can save named graphs in Virtuoso in format of context { subject predicate object ...} I want to know when we extract same triple ( subject predicate object ) from different contexts (for example, different web pages in Wikipedia or a news website), is it reasonable to save the same triples in different contexts? What's the best solution in Virtuoso to store same triples from different origins? 回答1: If you want to save the same triple values from

问题 I have a knowledge base in Virtuoso. I know we can save named graphs in Virtuoso in format of context { subject predicate object ...} I want to know when we extract same triple ( subject predicate object ) from different contexts (for example, different web pages in Wikipedia or a news website), is it reasonable to save the same triples in different contexts? What's the best solution in Virtuoso to store same triples from different origins? 回答1: If you want to save the same triple values from

问题 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? 回答1: 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

问题 I need to store RDF triples, while keeping track of modifications. Is there anything out there for this service? Alternatively, how would you keep track of revision while using a context-aware triplestore ? Edit : please note that I don't need only the changeset. I also need to see the triples at any time in the past. 回答1: I tried to address this sort of thing by storing additional triples describing who said what, when. But you need reification, named graphs, or quads which can ruin

问题 I need to store RDF triples, while keeping track of modifications. Is there anything out there for this service? Alternatively, how would you keep track of revision while using a context-aware triplestore ? Edit : please note that I don't need only the changeset. I also need to see the triples at any time in the past. 回答1: I tried to address this sort of thing by storing additional triples describing who said what, when. But you need reification, named graphs, or quads which can ruin

问题 I'm trying to install Ontotext GraphDB free on a debian jessie server. I've downloaded graphdb-free-8-1-1.deb file but when I'm typing the command sudo deb -i graphdb-free-8-1-1.deb as suggested in the quick start guide (http://graphdb.ontotext.com/documentation/free/quick-start-guide.html), I get the following message : sudo: deb: command not found It's seems that it has something to do with the /etc/sources.list file. Do I have to insert a line in this file ? how ? Thanks for your help. 回答1