3.3.11 Miscellaneous predicates
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  • Documentation
    • Reference manual
    • Packages
      • SWI-Prolog Semantic Web Library 3.0
        • Two RDF APIs
          • library(semweb/rdf_db): The RDF database
            • Miscellaneous predicates
              • rdf_bnode/1
              • rdf_source_location/2
              • rdf_generation/1
              • rdf_estimate_complexity/4
              • rdf_statistics/1
              • rdf_match_label/3
              • lang_matches/2
              • lang_equal/2
              • rdf_reset_db/0
              • rdf_version/1
Availability::- use_module(library(semweb/rdf_db)).
Source[nondet]rdf_statistics(?KeyValue)
Obtain statistics on the RDF database. Defined statistics are:
graphs(-Count)
Number of named graphs.
triples(-Count)
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.
resources(-Count)
Number of resources that appear as subject or object in a triple. See rdf_resource/1.
properties(-Count)
Number of current predicates. See rdf_current_predicate/1.
literals(-Count)
Number of current literals. See rdf_current_literal/1.
gc(GCCount, ReclaimedTriples, ReindexedTriples, Time)
Information about the garbage collector.
searched_nodes(-Count)
Number of nodes expanded by rdf_reachable/3 and rdf_reachable/5.
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, PendingResize)
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.