Struct PatternStats 

pub struct PatternStats {
    pub pattern: String,
    pub cardinality_estimate: usize,
    pub actual_cardinality: usize,
    pub evaluation_time_ms: u64,
    pub cache_hit: bool,
}

Execution statistics for a single triple-pattern within a query.

Fields

pattern: String

A human-readable identifier for the pattern (e.g. "?s rdf:type ?t").

cardinality_estimate: usize

The cardinality that the optimizer predicted before execution.

actual_cardinality: usize

The true cardinality observed during execution.

evaluation_time_ms: u64

Wall-clock time spent evaluating this pattern (milliseconds).

cache_hit: bool

Whether the result was served from a cache rather than evaluated.

Implementations

impl PatternStats

pub fn new( pattern: impl Into<String>, cardinality_estimate: usize, actual_cardinality: usize, evaluation_time_ms: u64, cache_hit: bool, ) -> Self

Construct a new PatternStats record.

pub fn cardinality_ratio(&self) -> f64

Ratio of actual to estimated cardinality; values < 1 mean the optimizer over-estimated, values > 1 mean it under-estimated.

Trait Implementations

impl Clone for PatternStats

fn clone(&self) -> PatternStats

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PatternStats

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

Formats the value using the given formatter.

impl PartialEq for PatternStats

fn eq(&self, other: &PatternStats) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for PatternStats