- rdf_predicate_property(?Predicate, ?Property)
- Query properties of a defined predicate. Currently defined
properties are given below.
- symmetric(Bool)
- True if the predicate is defined to be symetric. I.e., {A} P
{B} implies {B} P {A}. Setting symmetric is equivalent to
inverse_of(Self).
- inverse_of(Inverse)
- True if this predicate is the inverse of Inverse. This
property is used by rdf_has/3, rdf_has/4, rdf_reachable/3 and
rdf_reachable/5.
- transitive(Bool)
- True if this predicate is transitive. This predicate is
currently not used. It might be used to make rdf_has/3 imply
rdf_reachable/3 for transitive predicates.
- triples(Triples)
- Unify Triples with the number of existing triples using this
predicate as second argument. Reporting the number of triples
is intended to support query optimization.
- rdf_subject_branch_factor(-Float)
- Unify Float with the average number of triples associated with
each unique value for the subject-side of this relation. If
there are no triples the value 0.0 is returned. This value is
cached with the predicate and recomputed only after
substantial changes to the triple set associated to this
relation. This property is intended for path optimalisation
when solving conjunctions of rdf/3 goals.
- rdf_object_branch_factor(-Float)
- Unify Float with the average number of triples associated with
each unique value for the object-side of this relation. In
addition to the comments with the
rdf_subject_branch_factor
property, uniqueness of the object value is computed from the
hash key rather than the actual values.
- rdfs_subject_branch_factor(-Float)
- Same as
rdf_subject_branch_factor, but also considering
triples of `subPropertyOf' this relation. See also rdf_has/3.
- rdfs_object_branch_factor(-Float)
- Same as
rdf_object_branch_factor, but also considering
triples of `subPropertyOf' this relation. See also rdf_has/3.
- See also
- - rdf_set_predicate/2.