Struct PredicateStatistics 

pub struct PredicateStatistics {
    pub triple_count: u64,
    pub distinct_subjects: u64,
    pub distinct_objects: u64,
    pub is_functional: bool,
    pub is_inverse_functional: bool,
    pub object_type_distribution: HashMap<String, u64>,
    pub object_histogram: Option<Histogram>,
}

Statistics for a specific predicate (property).

Fields

triple_count: u64

Number of triples with this predicate.

distinct_subjects: u64

Number of unique subjects using this predicate.

distinct_objects: u64

Number of unique objects for this predicate.

is_functional: bool

Whether this predicate is functional (1 object per subject).

is_inverse_functional: bool

Whether this predicate is inverse functional (1 subject per object).

object_type_distribution: HashMap<String, u64>

Object type statistics (for typed literals).

object_histogram: Option<Histogram>

Histogram of object values (for selective filters).

Implementations

impl PredicateStatistics

pub fn new( triple_count: u64, distinct_subjects: u64, distinct_objects: u64, ) -> Self

Creates new predicate statistics.

pub fn with_functional(self, functional: bool) -> Self

Marks the predicate as functional.

pub fn with_object_histogram(self, histogram: Histogram) -> Self

Adds object histogram.

pub fn with_object_types(self, types: HashMap<String, u64>) -> Self

Adds object type distribution.

pub fn avg_objects_per_subject(&self) -> f64

Average number of objects per subject.

pub fn avg_subjects_per_object(&self) -> f64

Average number of subjects per object.

pub fn object_equality_selectivity(&self, _value: &Value) -> f64

Selectivity of a value equality filter on objects.

Trait Implementations

impl Clone for PredicateStatistics

fn clone(&self) -> PredicateStatistics

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for PredicateStatistics

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.