nLDE: Network of Linked Data Eddies

An adaptive query engine to execute SPARQL queries over Triple Pattern Fragments.

Download and Install

Download or clone this repository. Execute the following command in the main folder using Python 2.7.

[sudo] python setup.py install

Executing a SPARQL Query

To start a proxy, execute the following command:

nlde -s server -f queryfile 

nLDE supports several parameters:

• -s or --server: URL of the triple pattern fragment server (required)
• -f or --file: File name of the SPARQL query
• -q or --query: String with the SPARQL query
• -r or --results: Format of the output results Options: y prints the query answers and overall execution time statistics, n prints only the query answers, allprints the query answers with timestamps and overall execution time statistics.
• -t or --timeout: Query execution timeout in seconds

Example of Usage

In the following example, the query provided in the example folder is executed over a
DBpedia Triple Fragment server.

nlde-engine -s http://fragments.dbpedia.org/2014/en -f example/example.rq -r n

The nLDE answer looks as follows:

{'m': '"oral, intravenous"@en', 'sm1': '"[K+].O=C[C@@H]2N3C[C@@H][C@H]3SC2C.[O-]C[C@H]2C=C/CO"@en', 'd1': 'http://dbpedia.org/resource/Amoxicillin/clavulanic_acid'}
{'m': '"Oral, intravenous"@en', 'sm1': '"O=C[C@@H]2N3C[C@@H][C@H]3SC2C.Fc1ccccc1c2nocc2CN[C@@H]3CN4[C@@H]CS[C@H]34"@en', 'd1': 'http://dbpedia.org/resource/Ampicillin/flucloxacillin'}
{'m': '"Intravenous, intramuscular"@en', 'sm1': '"O.O[C@H][C@H]2CN1C\\C=O.OC[C@@H]CSCCCC\\C=CC=O"@en', 'd1': 'http://dbpedia.org/resource/Imipenem/cilastatin'}
{'m': '"Oral, intramuscular"@en', 'sm1': '"O=C[C@@H]2N3C[C@@H][C@H]3SC2C.CN[C@@H]2C=CCNCN5CCNCC5"@en', 'd1': 'http://dbpedia.org/resource/Penimepicycline'}
{'m': 'http://dbpedia.org/resource/Intravenous_therapy', 'sm1': '"O=C[C@@H]3N4C[C@@H][C@H]4SC3C.O=C3N2[C@@H][C@@]S[C@@H]2C3"@en', 'd1': 'http://dbpedia.org/resource/Piperacillin/tazobactam'}
example.rq	0.508171081543	1.43682408333	5

The statistics at the bottom indicate the time when the first answer was produced, the total execution time, and the number of answers.

How to Cite

Maribel Acosta, Maria-Esther Vidal: Networks of Linked Data Eddies: An Adaptive Web Query Processing Engine for RDF Data. International Semantic Web Conference (1) 2015: 111-127