README
Comunica SPARQL OSTRICH Init Actor
A comunica SPARQL OSTRICH Init Actor for querying versioned triple stores with OSTRICH.
This module is part of the Comunica framework.
Install
OSTRICH requires ZLib, Kyoto Cabinet and CMake (compilation only) to be installed.
$ yarn add @comunica/actor-init-sparql-ostrich
Usage from the command line
Show 100 triples from version 1 from an OSTRICH store:
$ comunica-sparql-ostrich ostrichFile@myStore.ostrich "CONSTRUCT WHERE { GRAPH <http://graph.version.1> { ?s ?p ?o } } LIMIT 100"
Show 100 triples from the latest version from an OSTRICH store:
$ comunica-sparql-ostrich ostrichFile@myStore.ostrich "CONSTRUCT WHERE { ?s ?p ?o } LIMIT 100"
Show the help with all options:
$ comunica-sparql-ostrich --help
Read more about querying from the command line.
Usage within application
This engine can be used in JavaScript/TypeScript applications as follows:
const newEngine = require('@comunica/actor-init-sparql-ostrich').newEngine;
const myEngine = newEngine();
const result = await myEngine.query(`
SELECT ?s ?p ?o WHERE {
?s ?p <http://dbpedia.org/resource/Belgium>.
?s ?p ?o
} LIMIT 100`, {
sources: [{ type: 'ostrichFile', value: 'myStore.ostrich' }],
});
// Consume results as a stream (best performance)
result.bindingsStream.on('data', (binding) => {
console.log(binding.get('?s').value);
console.log(binding.get('?s').termType);
console.log(binding.get('?p').value);
console.log(binding.get('?o').value);
});
// Consume results as an array (easier)
const bindings = await result.bindings();
console.log(bindings[0].get('?s').value);
console.log(bindings[0].get('?s').termType);
Read more about querying an application.
Usage as a SPARQL endpoint
Start a webservice exposing http://fragments.dbpedia.org/2015-10/en via the SPARQL protocol, i.e., a SPARQL endpoint.
$ comunica-sparql-ostrich-http ostrichFile@myStore.ostrich
Show the help with all options:
$ comunica-sparql-ostrich-http --help
The SPARQL endpoint can only be started dynamically.
An alternative config file can be passed via the COMUNICA_CONFIG
environment variable.
Use bin/http.js
when running in the Comunica monorepo development environment.