Stack Overflow
Stack Overflow

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.

127 questions
1
vote
0 answers

How to configure fuseki jena to use a reasoner and TDB + tdb:UnionDefaultGraph

Context i am new to fuseki, i am currently using it in a project, the main idea is: start the server with a pre-defined ontology (turtle file) + a reasoner I process files with python, and for each file, I generate an rdf graph that I put in a…
kam13
  • 11
  • 1
1
vote
1 answer

Does anyone know how to get the tdb2.dump command to actually do anything

I'm trying to dump a jena database as triples. There seems to be a command that sounds perfectly suited to the task: tdb2.dump jena@debian-clean:~$ ./apache-jena-3.8.0/bin/tdb2.tdbdump --help tdbdump : Write a dataset to stdout (defaults to…
Ben Hillier
  • 2,051
  • 1
  • 8
  • 14
1
vote
1 answer

How to Build a Fuseki TDB over a POST HTTP Request with Assembler.ttl? (How to send File over POST request)

https://jena.apache.org/documentation/fuseki2/fuseki-server-protocol.html Reading the documentation, we see that we are able to send a POST request containing assembler .ttl definitions to Fuseki Endpoint. Although, when trying that, my application…
Lucas Resende
  • 11
  • 1
1
vote
0 answers

JENA TDB load progression using Java API

I am wondering if it is possible to get load speed information when using the Java API. The code I have to load "large" files (few gb) is this: try (InputStream in = new FileInputStream(arguments.input)) { RDFParser.create() …
Jasper
  • 619
  • 1
  • 8
  • 18
1
vote
1 answer

What does Apache Jena's tdb2.tdbcompact do?

I have read the description of this command, but still don't know what it compresses, and why I should use it? BTW: the subdirectory Data-NNN is for previous and current versions of the databases, which means it can only have 1000 versions of the…
Gao
  • 690
  • 5
  • 14
1
vote
1 answer

What indices does jena TDB2 use?

I am trying to find out what indices TDB2 builds. I found out by the code that it uses B+ trees to store them on disc but I didn't get what they contain and how they are used. So my detailed questions are: For which collation order of RDF triples…
A. Bigerl
  • 45
  • 7
1
vote
1 answer

Is jena's fuseki not compactible with tdb2.tdbloader?

I have a requirement that incremental update tdb files daily. So I'm using tdb2.tdbloader to do the job with a generated N-Triples file. But when the job is done, the data directory which contains tdb data have a new directory called "data-0001" or…
Gao
  • 690
  • 5
  • 14
1
vote
1 answer

Jena TDB Dataset begin() fails

I want to use Jena TDB in a project. This is what I added in my POM: org.apache.jena apache-jena-libs 3.7.0 pom These are my…
Janothan
  • 368
  • 2
  • 15
1
vote
1 answer

SPARQL : OFFSET whithout ORDER BY to get all results of a query?

I have a large TDB dataset (cf. this post Fuseki config for 2 datasets + text index : how to use turtle files? ) and I need to extract data in order to make a "subgraph" and import it in fuseki. I found that OFFSET could be a solution to get all…
vvffl
  • 63
  • 8
1
vote
1 answer

Fuseki config for 2 datasets + text index : how to use turtle files?

I'm new to fuseki and want to use 2 TDB datasets for our project : a small one for our own data, and a large one (168 M triples, imported data from http://data.bnf.fr). We need to index the data because SPARQL queries using "FILTER(CONTAINS())"…
vvffl
  • 63
  • 8
1
vote
2 answers

Java OutOfMemoryError in apache Jena using TDB

Hi I've been using Jena for a project and now I am trying to query a Graph for storage in plain files for batch processing with Hadoop. I open a TDB Dataset and then I query by pages with LIMIT and OFFSET. I output files with 100000 triplets per…
Nord
  • 243
  • 2
  • 6
1
vote
0 answers

Fuseki 2 low performance

I have stored 80GB triples using FUSEKI 2 (latest version), which is actually a DbPedia dump. My problem happens when I run the following query. It is taking more than 5 minutes to return whereas at Snorql it takes less than one second. SELECT …
user7806
  • 38
  • 3
1
vote
1 answer

Can I use Apache Jena and persist the ontology using Apache Solr

We have a cloud base Java application that uses Oracle DB and Apache Solr for document indexing/searching. I need to implement an ontology and I intend to use Apache Jena. It's an uncharted territory for me. According to the docs, seems that using…
Jimo
  • 143
  • 1
  • 12
1
vote
1 answer

Does Jena TDB load all data into memory every time?

I am a newbie of Jena. I try to deal with the Yoga dataset using TDB. The dataset is about 200M and everytime I run the same query, it will have to take about 5 minutes to load the data then give out the results. I am wondering do I misunderstand…
Charlotte
  • 93
  • 11
1
vote
1 answer

command line tdbquery with text index

I trying to run a text search query with Jena via command line. tdbquery --desc textsearch.ttl --query search.rq The query return empty results with the messages: 17:23:46 WARN TextQueryPF :: Failed to find the text index : tried…
Samur Araujo
  • 11
  • 2
1 2
3
…
8 9