blob: 4ea2ab2c612d3c12522c4375f303710ccbbd5784 [file] [log] [blame]
<!DOCTYPE html>
<html lang="en">
<head>
<title>Apache Jena - TDB Assembler</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link href="/css/bootstrap.min.css" rel="stylesheet" media="screen">
<link href="/css/bootstrap-icons.css" rel="stylesheet" media="screen"><link rel="stylesheet" type="text/css" href="https://jena.apache.org/sass/jena.1b17c39a117e22b46db4c66f6395dc27c134a60377d87d2d5745b8600eb69722.css" integrity="sha256-GxfDmhF&#43;IrRttMZvY5XcJ8E0pgN32H0tV0W4YA62lyI=">
<link rel="shortcut icon" href="/images/favicon.ico" />
</head>
<body>
<nav class="navbar navbar-expand-lg bg-body-tertiary" role="navigation">
<div class="container">
<div class="navbar-header">
<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<a class="navbar-brand" href="/index.html">
<img class="logo-menu" src="/images/jena-logo/jena-logo-notext-small.png" alt="jena logo">Apache Jena</a>
</div>
<div class="collapse navbar-collapse" id="navbarNav">
<ul class="navbar-nav me-auto mb-2 mb-lg-0">
<li id="homepage" class="nav-item"><a class="nav-link" href="/index.html"><span class="bi-house"></span> Home</a></li>
<li id="download" class="nav-item"><a class="nav-link" href="/download/index.cgi"><span class="bi-download"></span> Download</a></li>
<li class="nav-item dropdown">
<a href="#" class="nav-link dropdown-toggle" role="button" data-bs-toggle="dropdown" aria-expanded="false"><span class="bi-journal"></span> Learn <b class="caret"></b></a>
<ul class="dropdown-menu">
<li class="dropdown-header">Tutorials</li>
<li><a class="dropdown-item" href="/tutorials/index.html">Overview</a></li>
<li><a class="dropdown-item" href="/documentation/fuseki2/index.html">Fuseki Triplestore</a></li>
<li><a class="dropdown-item" href="/documentation/notes/index.html">How-To's</a></li>
<li><a class="dropdown-item" href="/documentation/query/manipulating_sparql_using_arq.html">Manipulating SPARQL using ARQ</a></li>
<li><a class="dropdown-item" href="/tutorials/rdf_api.html">RDF core API tutorial</a></li>
<li><a class="dropdown-item" href="/tutorials/sparql.html">SPARQL tutorial</a></li>
<li><a class="dropdown-item" href="/tutorials/using_jena_with_eclipse.html">Using Jena with Eclipse</a></li>
<li class="dropdown-divider"></li>
<li class="dropdown-header">References</li>
<li><a class="dropdown-item" href="/documentation/index.html">Overview</a></li>
<li><a class="dropdown-item" href="/documentation/query/index.html">ARQ (SPARQL)</a></li>
<li><a class="dropdown-item" href="/documentation/io/">RDF I/O</a></li>
<li><a class="dropdown-item" href="/documentation/assembler/index.html">Assembler</a></li>
<li><a class="dropdown-item" href="/documentation/tools/index.html">Command-line tools</a></li>
<li><a class="dropdown-item" href="/documentation/rdfs/">Data with RDFS Inferencing</a></li>
<li><a class="dropdown-item" href="/documentation/geosparql/index.html">GeoSPARQL</a></li>
<li><a class="dropdown-item" href="/documentation/inference/index.html">Inference API</a></li>
<li><a class="dropdown-item" href="/documentation/ontology/">Ontology API</a></li>
<li><a class="dropdown-item" href="/documentation/permissions/index.html">Permissions</a></li>
<li><a class="dropdown-item" href="/documentation/extras/querybuilder/index.html">Query Builder</a></li>
<li><a class="dropdown-item" href="/documentation/rdf/index.html">RDF API</a></li>
<li><a class="dropdown-item" href="/documentation/rdfconnection/">RDF Connection - SPARQL API</a></li>
<li><a class="dropdown-item" href="/documentation/rdfstar/index.html">RDF-star</a></li>
<li><a class="dropdown-item" href="/documentation/shacl/index.html">SHACL</a></li>
<li><a class="dropdown-item" href="/documentation/shex/index.html">ShEx</a></li>
<li><a class="dropdown-item" href="/documentation/tdb/index.html">TDB</a></li>
<li><a class="dropdown-item" href="/documentation/tdb2/index.html">TDB2</a></li>
<li><a class="dropdown-item" href="/documentation/query/text-query.html">Text Search</a></li>
</ul>
</li>
<li class="nav-item dropdown">
<a href="#" class="nav-link dropdown-toggle" role="button" data-bs-toggle="dropdown" aria-expanded="false"><span class="bi-journal-code"></span> Javadoc <b class="caret"></b></a>
<ul class="dropdown-menu">
<li><a class="dropdown-item" href="/documentation/javadoc.html">All Javadoc</a></li>
<li><a class="dropdown-item" href="/documentation/javadoc/arq/">ARQ</a></li>
<li><a class="dropdown-item" href="/documentation/javadoc/fuseki2/">Fuseki</a></li>
<li><a class="dropdown-item" href="/documentation/javadoc/geosparql/">GeoSPARQL</a></li>
<li><a class="dropdown-item" href="/documentation/javadoc/jena/">Jena Core</a></li>
<li><a class="dropdown-item" href="/documentation/javadoc/permissions/">Permissions</a></li>
<li><a class="dropdown-item" href="/documentation/javadoc/extras/querybuilder/">Query Builder</a></li>
<li><a class="dropdown-item" href="/documentation/javadoc/shacl/">SHACL</a></li>
<li><a class="dropdown-item" href="/documentation/javadoc/tdb/">TDB</a></li>
<li><a class="dropdown-item" href="/documentation/javadoc/text/">Text Search</a></li>
</ul>
</li>
</ul>
<form class="d-flex" role="search" action="/search" method="GET">
<div class="input-group">
<input class="form-control border-end-0 border m-0" type="search" name="q" id="search-query" placeholder="Search...." aria-label="Search" style="width: 10rem;">
<button class="btn btn-outline-secondary border-start-0 border" type="submit">
<i class="bi-search"></i>
</button>
</div>
</form>
<ul class="navbar-nav">
<li id="ask" class="nav-item"><a class="nav-link" href="/help_and_support/index.html" title="Ask"><span class="bi-patch-question"></span><span class="text-body d-none d-xxl-inline"> Ask</span></a></li>
<li class="nav-item dropdown">
<a href="#" title="Get involved" class="nav-link dropdown-toggle" role="button" data-bs-toggle="dropdown" aria-expanded="false"><span class="bi-megaphone"></span><span class="text-body d-none d-xxl-inline"> Get involved </span><b class="caret"></b></a>
<ul class="dropdown-menu">
<li><a class="dropdown-item" href="/getting_involved/index.html">Contribute</a></li>
<li><a class="dropdown-item" href="/help_and_support/bugs_and_suggestions.html">Report a bug</a></li>
<li class="dropdown-divider"></li>
<li class="dropdown-header">Project</li>
<li><a class="dropdown-item" href="/about_jena/about.html">About Jena</a></li>
<li><a class="dropdown-item" href="/about_jena/architecture.html">Architecture</a></li>
<li><a class="dropdown-item" href="/about_jena/citing.html">Citing</a></li>
<li><a class="dropdown-item" href="/about_jena/team.html">Project team</a></li>
<li><a class="dropdown-item" href="/about_jena/contributions.html">Related projects</a></li>
<li><a class="dropdown-item" href="/about_jena/roadmap.html">Roadmap</a></li>
<li><a class="dropdown-item" href="/about_jena/security-advisories.html">Security Advisories</a></li>
<li class="dropdown-divider"></li>
<li class="dropdown-header">ASF</li>
<li><a class="dropdown-item" href="https://www.apache.org/">Apache Software Foundation</a></li>
<li><a class="dropdown-item" href="https://www.apache.org/foundation/sponsorship.html">Become a Sponsor</a></li>
<li><a class="dropdown-item" href="https://www.apache.org/licenses/LICENSE-2.0">License</a></li>
<li><a class="dropdown-item" href="https://www.apache.org/security/">Security</a></li>
<li><a class="dropdown-item" href="https://www.apache.org/foundation/thanks.html">Thanks</a></li>
</ul>
</li>
<li class="nav-item" id="edit"><a class="nav-link" href="https://github.com/apache/jena-site/edit/main/source/documentation/tdb/assembler.md" title="Edit this page on GitHub"><span class="bi-pencil-square"></span><span class="text-body d-none d-xxl-inline"> Edit this page</span></a></li>
</ul>
</div>
</div>
</nav>
<div class="container">
<div class="row">
<div class="col-md-12">
<div id="breadcrumbs">
<ol class="breadcrumb mt-4 p-2 bg-body-tertiary">
<li class="breadcrumb-item"><a href='/documentation'>DOCUMENTATION</a></li>
<li class="breadcrumb-item"><a href='/documentation/tdb'>TDB</a></li>
<li class="breadcrumb-item active">ASSEMBLER.HTML</li>
</ol>
</div>
<h1 class="title">TDB Assembler</h1>
<main class="d-flex flex-xl-row flex-column">
<aside class="text-muted align-self-start mb-3 p-0 d-xl-none d-block">
<h2 class="h6 sticky-top m-0 p-2 bg-body-tertiary">On this page</h2>
<nav id="TableOfContents">
<ul>
<li><a href="#dataset">Dataset</a>
<ul>
<li><a href="#union-default-graph">Union Default Graph</a></li>
</ul>
</li>
<li><a href="#graph">Graph</a></li>
<li><a href="#mixed-datasets">Mixed Datasets</a></li>
<li><a href="#rdfs">RDFS</a></li>
</ul>
</nav>
</aside>
<article class="flex-column me-lg-4">
<p><a href="/documentation/assembler/">Assemblers</a>
are a general mechanism in Jena to describe objects to be built,
often these objects are models and datasets. Assemblers are used
heavily in <a href="../fuseki2/">Fuseki</a> for
dataset and model descriptions, for example.</p>
<p>SPARQL queries operate over an
<a href="http://www.w3.org/TR/sparql11-query/#rdfDataset" title="http://www.w3.org/TR/rdf-sparql-query/#rdfDataset">RDF dataset</a>,
which is an unnamed, default graph and zero or more named graphs.</p>
<p>Having the description in a file means that the data that the
application is going to work on can be changed without changing the
program code.</p>
<h2 id="dataset">Dataset</h2>
<p>This is needed for use in <a href="../fuseki2/" title="Fuseki">Fuseki</a>.</p>
<p>A dataset can be constructed in an assembler file:</p>
<pre><code>PREFIX tdb: &lt;http://jena.hpl.hp.com/2008/tdb#&gt;
PREFIX rdf: &lt;http://www.w3.org/1999/02/22-rdf-syntax-ns#&gt;
PREFIX rdfs: &lt;http://www.w3.org/2000/01/rdf-schema#&gt;
PREFIX ja: &lt;http://jena.hpl.hp.com/2005/11/Assembler#&gt;
&lt;#dataset&gt; rdf:type tdb:DatasetTDB ;
tdb:location &quot;DB&quot; ;
.
</code></pre>
<p>Only one dataset can be stored in a location (filing system
directory).</p>
<p>The first section declares the prefixes used later:</p>
<pre><code>PREFIX tdb: &lt;http://jena.hpl.hp.com/2008/tdb#&gt;
PREFIX rdf: &lt;http://www.w3.org/1999/02/22-rdf-syntax-ns#&gt;
PREFIX rdfs: &lt;http://www.w3.org/2000/01/rdf-schema#&gt;
PREFIX ja: &lt;http://jena.hpl.hp.com/2005/11/Assembler#&gt;
</code></pre>
<p>then there is the description of the TDB dataset itself:</p>
<pre><code>&lt;#dataset&gt; rdf:type tdb:DatasetTDB ;
tdb:location &quot;DB&quot; ;
</code></pre>
<p>The property <code>tdb:location</code> gives the file name as a string. It is
relative to the applications current working directory, not where
the assembler file is read from.</p>
<p>The dataset description is usually found by looking for the one
subject with type <code>tdb:GraphDataset</code>. If more than one graph is
given in a single file, the application will have to specify which
description it wishes to use.</p>
<h3 id="union-default-graph">Union Default Graph</h3>
<p>An assembler can specify that the default graph for query is the
union of the named graphs. This is done by adding
<em>tdb:unionDefaultGraph</em>.</p>
<pre><code>&lt;#dataset&gt; rdf:type tdb:DatasetTDB ;
tdb:location &quot;DB&quot; ;
tdb:unionDefaultGraph true ;
.
</code></pre>
<h2 id="graph">Graph</h2>
<p>TDB always stores data in an RDF dataset. It is possible to use
just one of the graphs from the dataset. A common way of working
with one graph is to use the default graph of the dataset.</p>
<p>A single graph from a TDB dataset can be described by:</p>
<pre><code>PREFIX tdb: &lt;http://jena.hpl.hp.com/2008/tdb#&gt;
PREFIX rdf: &lt;http://www.w3.org/1999/02/22-rdf-syntax-ns#&gt;
PREFIX rdfs: &lt;http://www.w3.org/2000/01/rdf-schema#&gt;
PREFIX ja: &lt;http://jena.hpl.hp.com/2005/11/Assembler#&gt;
&lt;#dataset&gt; rdf:type tdb:DatasetTDB ;
tdb:location &quot;DB&quot; ;
&lt;#graph&gt; rdf:type tdb:GraphTDB ;
tdb:dataset &lt;#dataset&gt; .
</code></pre>
<p>A particular named graph in the dataset at a location can be
assembled with:</p>
<pre><code>&lt;#graphNamed&gt; rdf:type tdb:GraphTDB ;
tdb:dataset &lt;#dataset&gt; ;
tdb:graphName &lt;http://example/graph1&gt; ;
.
</code></pre>
<h2 id="mixed-datasets">Mixed Datasets</h2>
<p>It is possible to create a dataset with graphs backed by different
storage subsystems, although query is not necessarily as
efficient.</p>
<p>To include as a named graph in a dataset use vocabulary as shown
below:</p>
<pre><code>PREFIX tdb: &lt;http://jena.hpl.hp.com/2008/tdb#&gt;
PREFIX rdf: &lt;http://www.w3.org/1999/02/22-rdf-syntax-ns#&gt;
PREFIX rdfs: &lt;http://www.w3.org/2000/01/rdf-schema#&gt;
PREFIX ja: &lt;http://jena.hpl.hp.com/2005/11/Assembler#&gt;
# A dataset of one TDB-backed graph as the default graph and
# an in-memory graph as a named graph.
&lt;#dataset&gt; rdf:type ja:RDFDataset ;
ja:defaultGraph &lt;#graph&gt; ;
ja:namedGraph
[ ja:graphName &lt;http://example.org/name1&gt; ;
ja:graph &lt;#graph2&gt; ] ;
.
&lt;#graph&gt; rdf:type tdb:GraphTDB ;
tdb:location &quot;DB&quot; ;
.
&lt;#graph2&gt; rdf:type ja:MemoryModel ;
ja:content [ja:externalContent &lt;file:Data/books.n3&gt; ] ;
.
</code></pre>
<p>Note here we added:</p>
<pre><code>tdb:DatasetTDB rdfs:subClassOf ja:RDFDataset .
tdb:GraphTDB rdfs:subClassOf ja:Model .
</code></pre>
<p>which provides for integration with complex model setups, such as
reasoners.</p>
<h2 id="rdfs">RDFS</h2>
<pre><code>PREFIX tdb: &lt;http://jena.hpl.hp.com/2008/tdb#&gt;
PREFIX rdf: &lt;http://www.w3.org/1999/02/22-rdf-syntax-ns#&gt;
PREFIX rdfs: &lt;http://www.w3.org/2000/01/rdf-schema#&gt;
PREFIX ja: &lt;http://jena.hpl.hp.com/2005/11/Assembler#&gt;
tdb:Dataset a rdfs:Class .
tdb:GraphTDB a rdfs:Class .
tdb:DatasetTDB rdfs:subClassOf ja:RDFDataset .
tdb:GraphTDB rdfs:subClassOf ja:Model .
tdb:location a rdf:Property ;
# domain is tdb:Dataset or tdb:GraphTDB
# The range is simple literal
.
tdb:unionDefaultGraph a rdf:Property ;
rdfs:domain tdb:Dataset ;
# The range is xsd:boolean
.
tdb:graphName a rdf:Property ;
rdfs:domain tdb:GraphTDB ;
# range is a URI
.
</code></pre>
</article>
<aside class="text-muted align-self-start mb-3 mb-xl-5 p-0 d-none d-xl-flex flex-column sticky-top">
<h2 class="h6 sticky-top m-0 p-2 bg-body-tertiary">On this page</h2>
<nav id="TableOfContents">
<ul>
<li><a href="#dataset">Dataset</a>
<ul>
<li><a href="#union-default-graph">Union Default Graph</a></li>
</ul>
</li>
<li><a href="#graph">Graph</a></li>
<li><a href="#mixed-datasets">Mixed Datasets</a></li>
<li><a href="#rdfs">RDFS</a></li>
</ul>
</nav>
</aside>
</main>
</div>
</div>
</div>
<footer class="bd-footer py-4 py-md-5 mt-4 mt-lg-5 bg-body-tertiary">
<div class="container" style="font-size:80%" >
<p>
Copyright &copy; 2011&ndash;2024 The Apache Software Foundation, Licensed under the
<a href="https://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.
</p>
<p>
Apache Jena, Jena, the Apache Jena project logo, Apache and the Apache feather logos are trademarks of
The Apache Software Foundation.
<br/>
<a href="https://privacy.apache.org/policies/privacy-policy-public.html"
>Apache Software Foundation Privacy Policy</a>.
</p>
</div>
</footer>
<script src="/js/popper.min.js.js" type="text/javascript"></script>
<script src="/js/bootstrap.min.js" type="text/javascript"></script>
<script src="/js/improve.js" type="text/javascript"></script>
<script type="text/javascript">
(function() {
'use strict'
const links = document.querySelectorAll(`a[href="${window.location.pathname}"]`)
if (links !== undefined && links !== null) {
for (const link of links) {
link.classList.add('active')
let parentElement = link.parentElement
let count = 0
const levelsLimit = 4
while (['UL', 'LI'].includes(parentElement.tagName) && count <= levelsLimit) {
if (parentElement.tagName === 'LI') {
parentElement.querySelector('a:first-child').classList.add('active')
}
parentElement = parentElement.parentElement
count++
}
}
}
})()
</script>
</body>
</html>