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Using other triplestores

Configuring an existing triplestore

It is possible to use the built-in triplestore, or you can use Shmarql to act as a front-end to an existing triplestore. Popular choices would be products like Virtuoso, Fuseki, GraphDB, QLever or Oxigraph. You then install, configure and run a triplestore separately from the Shmarql installation and "point" at your existing triplestore by configuring the ENDPOINT variable. For example:

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docker run --rm -it -p 8000:8000 \
     -e ENDPOINT=http://192.168.1.15:8890/sparql \
     ghcr.io/epoz/shmarql

The above will provide a Shmarql view of a Virtuoso instance running on an IP address that can be reached from inside the Shmarql container. This could also be any existing public SPARQL endpoint.

Multiple Endpoints

It is also possible to have multiple endpoints exposed, for performance, reliability or testing reasons. Use the ENDPOINTS variable, with a space-separated list of addresses prefixed with a name + | symbol, for example:

virtuoso|http://192.168.1.15:8890/sparql qlever|http://192.168.1.15:7019/

The Shmarql query processor will choose one of the endpoints at random to service requests, or you can explicitly choose an endpoint to use by adding a comment to you SPARQL query, of the form # shmarql-engine: some_name where some_name is one of the names used in your ENDPOINTS variable.

For example, using this run command:

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docker run --rm -it  -p 8000:8000 \
    -e 'virtuoso|http://192.168.1.15:8890/sparql qlever|http://192.168.1.15:7019/' \
    ghcr.io/epoz/shmarql

you can specify the endpoint in a query like so:

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# shmarql-engine: qlever
select * where {?s ?p ?o} limit 42