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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 to subquery with filters in jena sparql?

I am trying to apply a Subquery in filters in Jena Sparql.Is this possible.If yes,how?eg: SELECT ?x WHERE(?y ?z . ?y ?x .FILTER regex(?z,subquery,"i")} I mean I want to give the expression in filter using some subquery in jena..How…
cooljohny
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How to do multiple add operation apache jena tdb

I have to serialize some specific properties (about ten film's properties) for a set of 1500 entity from DBpedia. So for each entity I run a sparql query in order to retrieve them and after that, for each ResultSet I store all the data in the tdb…
Alessandro Suglia
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How to perform delete query in jena sparql?

This question might sound lame but I am really confused...This is my code for normal query : public class test4query extends Object { public static String[] arr=new String[30]; public void mai (String s) { String directory =…
cooljohny
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errors in transaction in jena tdb?

I am trying to write propreties into a model and then query it.This part of mycode: String directory = "EMAILADDRESS" ; //create the dataset for the tdb store Dataset ds = TDBFactory.createDataset(directory) ; //create default rdf…
cooljohny
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Loading a .trig file into TDB?

I am currently writing some code in Java, using Jena and TDB -- on a Windows 7. I want to be able to load a (large) .trig file into TDB Dataset so that querying is a bit faster. The code that I currently have is: Dataset dataset =…
user2570374
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How to create an .owl file from apache JENA TDB

I can currently load an .owl file into a dataset and commit it to JENA TDB. How can I go the other direction? In other words, how can I get all the information in the TDB and put it in an .owl file (rdf/xml using the JENA api)?
Nick
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Locking only part of a dataset in Apache Jena TDB

I am making a web application which will store a .owl file in a Jena TDB. The TDB will be stored in memory on a server. When a user writes to the TDB, it seems like it will place a write lock on the entire TDB. Is there a way to lock only a part…
Nick
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Upload .nt/tdb file to protege

I am trying to load diff formats of ontology file like OWL, RDF , .nt, TDB. I want to upload .nt/TDB file in protege. My nt(ntriple) file is in 40gb. Will protege support this.
JJJ
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How to efficiently load a rdf file for query

I am using Apache Jena's tdbloader for a query-based web application. My web app selects a particular database (a Turtle file) and loads it. Currently I am using the standard tdbloader to load the selected file. However, it takes about fifteen…
Aryabhatt
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In which conditions Jena turns to parallel?

I've run queries on Jena TDB and Jena In memory triple store, both on a single core machine and on a machine with 16 CPUs. I observe that in 16Cores machine Jena spawns lot of threads to handle both query and inference operations. So I wonder, does…
Fopa Léon Constantin
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TDBFactory not found in jena-tdb-0.9.4.jar?

I'm have download a jena-2.6.4 zip to manage a triple store. In this zip there was lib directory with libraries, and jena-tdb-0.9.4.jar was amount them. However while trying the simplest following code import com.hp.hpl.jena.tdb.*; ... String…
Fopa Léon Constantin
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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…
rcantonialli
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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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