4store
2009-07-08
4store
RDF database storage and query engine -- database daemon
NAME
4s-query - Run SPARQL queries on a 4store storage backend
SYNOPSIS
4s-query kb-name [-f format] [-O optimisation-level] [-I insert-mode] [-r] [-s soft-limit] [-b base-URI] [-e] [-P] [query]
| -f | Set the format to output results it, options are "sparql", "text", "json", and "testcase" |
| -O, --opt-level | |
| Set the optimisation level of the query engine, in the range 0-3. | |
| -I, --insert | |
| Treat CONSTRUCT statements as INSERT statements. This feature is highly experimental and largely untested. | |
| -r, --restricted | |
| Enable query complexity restriction mode | |
| -s, --soft-limit | |
| Override default soft limit on search breadth | |
| -d, --default-graph | |
| Enable SPARQL default graph support | |
| -b, --base | |
| Set base URI for queries | |
| -e, --explain | |
| Return an explanation of the query planner’s decisions | |
| -P | Enable programatic IO mode |
INTERACTIVE MODE
If [query] is omitted then 4s-query goes into interactive mode, suitable for trying queries from the command line.
-P enables programmatic interactive mode, suitable for interfacing with processes via stdin and stdout. Queries are sent as UTF-8 bytes, terminated with "#EOQ" on a line of it’s own, results are returned, ending with "#EOR". Interacting with 4store in this way is more efficient than using the SPARQL protocol, but non-standard.
SEE ALSO
4s-import(1), 4s-httpd(1), 4s-backend(1), 4s-delete-model(1)
STANDARDS
4s-query implements the SPARQL Query Language specification (aka. SPARQL/Query 1.0) and the SPARQL Result Format specification (aka. SPARQL/Results 1.0).
Default graph support is no normally enabled, the --default-graph turns it on, as does specifying FROM <default:> in the query. Data loaded with
$ 4s-import kb --add -m default: uri/filename
will be added to the default graph.
EXAMPLES
$ 4s-query -f sparql demo ’SELECT * WHERE { ?s ?p ?s } LIMIT 10’
Return 10 random triples from the knowledgebase "demo" in the SPARQL XML result format.
$ 4s-query -P demo < query.rq
Run the query in query.rq and output the result to stdout
