Struct PredicateStats 

pub struct PredicateStats {
    pub fact_count: usize,
    pub rule_count: usize,
    pub avg_arity: f64,
    pub estimated_cardinality: f64,
    pub selectivity: f64,
}

Statistics for a single predicate

Fields

fact_count: usize

Number of facts for this predicate

rule_count: usize

Number of rules with this predicate as head

avg_arity: f64

Average arity (number of arguments)

estimated_cardinality: f64

Estimated cardinality after filtering

selectivity: f64

Selectivity (0.0 = highly selective, 1.0 = not selective)

Implementations

impl PredicateStats

pub fn new(fact_count: usize, rule_count: usize, avg_arity: f64) -> Self

Create new stats

pub fn compute_selectivity(&mut self, total_facts: usize)

Compute selectivity based on total facts

Trait Implementations

impl Clone for PredicateStats

fn clone(&self) -> PredicateStats

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PredicateStats

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

Formats the value using the given formatter.

impl Default for PredicateStats

fn default() -> PredicateStats

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for PredicateStats

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for PredicateStats

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.