Execute SPARQL queries using the Jena ARQ command-line utility. – Linked Data for Professional Education

Jena Full Text Search

Sun, 13 Aug 2017 08:18:11 +0000

This documentation explains how to configure and use the Full Text extension to Apache Jena's ARQ (the module is included in Fuseki). The extension combines SPARQL and full-text search via Lucene or ElasticSearch (built on Lucene). It gives applications the ability to perform indexed full-text searches within SPARQL queries. Although SPARQL allows the use of regular expressions in FILTER, this is a test on a value retrieved earlier in the query and its use is not indexed. In other words, if you're searching for occurrences of a specific term in the rdfs:label of a bunch of products, then the search will need to examine all selected rdfs:label statements and apply the regular expression to each label in turn. If there are many such statements and many such uses of regex, then it may be appropriate to consider using this extension to take advantage of the performance potential of full text indexing.

URL: http://jena.apache.org/documentation/query/text-query.html
Keywords: SPARQL, REGEX, FILTER, Apache Jena
Publisher: Apache Jena
Language: http://id.loc.gov/vocabulary/iso639-2/eng
Time required: P2H
Educational use: professionalDevelopment

]]>

Querying Linked Data with SPARQL

Thu, 13 Aug 2015 03:26:21 +0000

This slideset was part of the "How to Consume Linked Data" tutorial at the International Semantic Web Conference (ISWC), Oct. 2009. Predates SPARQL 1.1, so some of the information on federated queries may be outdated. However, this resource is of particular interest to those wishing to learn about automated link traversal.

URL: http://www.slideshare.net/olafhartig/querying-linked-data-with-sparql?related=2
Keywords: SQUIN, SPARQL endpoint, Link traversal based query execution (LTBQE), Automated link traversal
Author: Hartig, Olaf
Date created: 2009-10-25 07:00:00.000
Language: http://id.loc.gov/vocabulary/iso639-2/eng
Time required: P45M
Educational use: instruction
Educational audience: generalPublic
Interactivity type: expositive

]]>

SPARQL Tutorial: A First SPARQL Query

Thu, 13 Aug 2015 03:26:16 +0000

A brief, text-based tutorial demonstrating a simple first query and how to execute it with Apache Jena. Shows how to formulate a simple command line query using SELECT and WHERE, then execute it using ARQ. Contains a brief overview of how variables and fixed values work.

URL: http://jena.apache.org/tutorials/sparql_query1.html
Keywords: ARQ, Apache Jena, SPARQL
Publisher: The Apache Software Foundation
Language: http://id.loc.gov/vocabulary/iso639-2/eng
Time required: P10M
Educational use: instruction
Educational audience: student
Interactivity type: active

]]>