Questions tagged [blazegraph]

Blazegraph is an open-source RDF/graph database capable of clustered deployment. This tag is specific for questions on the database API. RDF and SPARQL are often related technologies.

Overview

Blazegraph is an open-source, ultra-scalable, high-performance graph database written in Java. It supports various technologies such as:

Blazegraph offers different operating modes (triples, provenance, and quads) and either operates as an embedded database or over a client/server REST API.

Blazegraph supports up to 50 billion edges on a single machine and has a high availability and scale-out architecture. It is in production use for Fortune 500 customers such as EMC, Autodesk, and many others. It was selected by the Wikimedia foundation to power their Wikidata query service.

Documentation links

The official Blazegraph website can be found here. In-depth technical details on the graph database can be found in the official Blazegraph Wiki. The Blazegraph API itself is documented on GitHub.

Background information on the big-data architecture, internals, and deployment models can be found in several white papers in the Blazegraph Blog.

When to use this tag

Please use the tag on questions about the database API. If you have a more general question to which an answer might not necessarily depend on the Blazegraph API, please consider including or .

If you want to discuss or suggest Blazegraph features, please do it via the Blazegraph contact page.

Related tags

Adapted from the Blazegraph website and the Blazegraph Wiki.

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Convert TTL output into RDF triples readable by BlazeGraphDB

I am working on an NLP pipeline that takes a collection of textual records as input and extracts entities and relationships within the text of each record. The pipeline utilizes the spaCy library for named entity extraction and BLINK for linking…
Youcef
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How to filter IRI correctly in Blazegraph RDF?

How can I make a proper SPARQL query to filter out entities using their IRI? Currently, I am getting empty set when I try to filter by IRI. I am using Blazegraph DB and I run this SPARQL query: SELECT ?y ?p ?g WHERE > { ?y ?p ?g . FILTER regex(?g,…
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SPARQL: Service with dynamic IRI

I want to query an .owl remotely using the IRIs provided in another .owl file. For example: The base file:
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Trying to run a sparql query on quads+triples files, getting error: com.bigdata.rdf.sparql.ast.QuadsOperationInTriplesModeException

I am using the Blazegraph Database to run a very simple query. For my dataset, I have .ttl and .nq files. I am loading the files using Blazegraph's Bulk Data Loader. Here is my query: SELECT DISTINCT ?g WHERE { GRAPH ?g { ?s ?p ?o } } I expect an…
Shivika P
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How to fix bound sparql query not working as expected?

I have this sparql query that I need to modify. I have the example instance, which has the exampleID 12345. For this case, if the :hasRelatedExample connection exists, the ?test variable will become 2. If the :hasRelatedExample connection doesn't…
moro_92
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Retrieve Wikidata Item Wiki url with SPARQL

I'm using this approach to retrieve the Wikipedia url for a Wikidata item for multiple languages, using Sparql: SELECT ?item ?en ?url_en ?es WHERE { { ?item wdt:P31 wd:Q6256. } UNION { ?item wdt:P31 wd:Q1250464. } UNION { ?item wdt:P31…
loretoparisi
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SPARQL Wikidata Query to retrieve url for multiple languages

I wrote this Sparql query to retrieve item labels in multiple language SELECT ?item ?en ?es ?it WHERE { { ?item wdt:P31 wd:Q6256. } UNION { ?item wdt:P31 wd:Q1250464. } UNION { ?item wdt:P31 wd:Q3624078. } UNION { ?item wdt:P31…
loretoparisi
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Is there a way to efficiently execute ORDER BY + LIMIT using an index in Blazegraph?

I am playing with Blazegraph. I insert some triples representing 'events', each of 'event' contains 3 triples and looks like this: <%event-iri%> '2020-01-02T03:04:05.000Z'^^xsd:dateTime . <%event-iri%>…
Roman Puchkovskiy
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Does Blazegraph support range query optimization?

I am playing with Blazegraph. I insert some triples representing 'events', each of 'event' contains 3 triples and looks like this: <%event-iri%> '2020-01-02T03:04:05.000Z'^^xsd:dateTime . <%event-iri%>…
Roman Puchkovskiy
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How to host my own triplestore using blazegraph?

I am new to using Blazegraph and am have been developing with it locally as part of a project over the past few months. I am currently trying to host an instance of my triple store online and have got to the point where I am lost going around in…
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Problem while running a Jar file in ubuntu

I am not very familiar with the Ubuntu. I have moved a jar file relatd to Blazegraph which I used on my Windows machine to my Ubuntu VM (Ubuntu 18.04 LTS Bionic). I have also used chmod +x filename to make it executable. But when running the file,…
RFAI
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I cannot export data in some formats using the Blazegraph web interface

I am trying to export all the data in one namespace from my blazegraph instance via the web interface. After I run a query and get some results I hit the "Export" button. The export function gives me the option of exporting as csv, json and xml. But…
Daniel Mermelstein
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How to get JSON returned from POSTing text/turtle to Blazegraph?

My update is working because I can query the data I'd sent, but the response I get is in XML: I am setting the request header Accept: con.setRequestProperty("Accept",…
wnm3
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404 Not Found on load from Jena into Blazegraph

I have a simple piece of code using Jena's RDFConnection to load rdf into Blazegraph, but keep getting HTTP 404 Not found: public void simpleLoad() { String service = "http://localhost:8889/bigdata"; try ( RDFConnection conn =…
estoy
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Possible causes for an intermittent IOException error?

I am attempting to write to a Blazegraph database file multiple times using the OpenRDF Java API. Here is some pseudocode that mimics what I'm trying to do: //create Connection to the database Repository repo = new…
hayfreed
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