An adaptive query engine to execute SPARQL queries over Triple Pattern Fragments.
Download or clone this repository. Execute the following command in the main folder using Python 2.7.
[sudo] python setup.py install
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,all
prints the query answers with timestamps and overall execution time statistics.-t
or--timeout
: Query execution timeout in seconds
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.
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