[nondet]rdf_statistics(?KeyValue)Obtain statistics on the RDF database. Defined statistics are:
- Number of named graphs.
- Total number of triples in the database. This is the number of asserted
triples minus the number of retracted ones. The number of visible
triples in a particular context may be different due to visibility rules
defined by the logical update view and transaction isolation.
- Number of resources that appear as subject or object in a triple. See rdf_resource/1.
- Number of current predicates. See rdf_current_predicate/1.
- Number of current literals. See rdf_current_literal/1.
- gc(GCCount, ReclaimedTriples,
- Information about the garbage collector.
- Number of nodes expanded by rdf_reachable/3
- lookup(rdf(S,P,O,G), Count)
- Number of queries that have been performed for this particular
instantiation pattern. Each of S,P,O,G
is either + or -. Fails in case the number of performed queries is zero.
- hash_quality(rdf(S,P,O,G), Buckets, Quality,
- Statistics on the index for this pattern. Indices are created lazily on
the first relevant query.
- triples_by_graph(Graph, Count)
- This statistics is produced for each named graph. See
triples for the interpretation of this value.