Questions tagged [tdb]

TDB is an open source RDF database developed and maintained by the Apache Jena project

TDB is an open source RDF database developed and maintained by the Apache Jena project. It is a Java based embedded database that may be exposed over HTTP using the Fuseki Server also from the Apache Jena project.

Features

It's features includes the following:

  • Persisting RDF Triples or Quads
  • Full SPARQL execution
  • Write ahead logging to provide serializable transactions and fault tolerance

Scalability and Performance

TDB typically scales up to datasets of a few hundred million triples or quads.

Compared to commercial alternatives TDB is often less scalable compared primarily because while it is persisted to disk it is fundamentally designed as an in-memory database. It relays heavily on RAM caches and memory mapped files so scalability tends to be limited by machine RAM.

Also TDB does not have any option of a clustered mode so cannot be scaled horizontally without additional technologies (e.g. manually created replicas and load balancers)

TDB is typically included in the Berlin SPARQL Benchmark Results for those interested in comparative performance data.

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How Can I Load two ontologies in one model

I posted other questions about this problem...But I think that I'm near the solution. I have this code that works ONLY with the loading of "dbpedia.owl". The problem appears when I add the other ontology "yago.nt"...I have…
user2837896
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owl:imports in Fuseki

I'm new here, and although I've searched for something like this, I couldn't find an answer. So here is my question: How Fuseki handles owl:imports? Details: I've defined a set of ontologies in different owl files. Let's call two of them of…
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Creating a Lucene index for an existing Apache Jena TDB to implement text search

I have a large Apache Jena TDB, I want to build a Lucene index using Apache Jena 2.10.2 for use with the new text search feature. I find the documentation hard to follow. I first tried to use configuration in code, but had trouble with the…
bmoran
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size limit on Jena/TDB archives

We are working in a big project (with a lot of metadata) using Jena TDB. About a month ago a problem regarding memory appeared suddenly—the program has been working properly for months and no changes were done—and we are not able to upload any more…
Paco
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Jena: Getting an empty result set

I am getting an empty result set when I try to retrieve the data stored in a jena model. This is the code to load the data (I have removed the imports for brevity) package basic; //imports here public class DataLoaderQn { public static…
ramp
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Is it possible to add virtuoso as a storage provider in Jena-Fuseki?

I am trying to set up virtuoso as a storage provider service inside Jena-Fuseki config.ttl file is it possible to add this service as RDF database to Fuseki, is it a right way or I must have to add virtuoso.jena.driver Packege inside…
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error in addproperty and addliteral function

I am trying to store my emails in rdf models into apche tdb. Here's my code : /*Program to download the mails from mail servers and then to store them in tdb store using rdf model*/ //import all the classes needed import java.io.*; import…
cooljohny
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