Struct Statistics 

pub struct Statistics {
    pub labels: HashMap<String, LabelStatistics>,
    pub edge_types: HashMap<String, EdgeTypeStatistics>,
    pub properties: HashMap<PropertyKey, ColumnStatistics>,
    pub total_nodes: u64,
    pub total_edges: u64,
}

Statistics for the entire database.

Fields

labels: HashMap<String, LabelStatistics>

Per-label statistics.

edge_types: HashMap<String, EdgeTypeStatistics>

Per-edge-type statistics.

properties: HashMap<PropertyKey, ColumnStatistics>

Per-property statistics (across all labels).

total_nodes: u64

Total node count.

total_edges: u64

Total edge count.

Implementations

impl Statistics

pub fn new() -> Self

Creates a new empty statistics object.

pub fn update_label(&mut self, label: &str, stats: LabelStatistics)

Updates label statistics.

pub fn update_edge_type(&mut self, edge_type: &str, stats: EdgeTypeStatistics)

Updates edge type statistics.

pub fn update_property(&mut self, property: &str, stats: ColumnStatistics)

Updates property statistics.

pub fn get_label(&self, label: &str) -> Option<&LabelStatistics>

Gets label statistics.

pub fn get_edge_type(&self, edge_type: &str) -> Option<&EdgeTypeStatistics>

Gets edge type statistics.

pub fn get_property(&self, property: &str) -> Option<&ColumnStatistics>

Gets property statistics.

pub fn estimate_label_cardinality(&self, label: &str) -> f64

Estimates the cardinality of a label scan.

pub fn estimate_avg_degree(&self, edge_type: &str, outgoing: bool) -> f64

Estimates the average degree for an edge type.

pub fn estimate_equality_selectivity( &self, property: &str, _value: &Value, ) -> f64

Estimates selectivity of an equality predicate.

pub fn estimate_range_selectivity( &self, property: &str, lower: Option<&Value>, upper: Option<&Value>, ) -> f64

Estimates selectivity of a range predicate.

Trait Implementations

impl Clone for Statistics

fn clone(&self) -> Statistics

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Statistics

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

Formats the value using the given formatter.

impl Default for Statistics

fn default() -> Statistics

Returns the “default value” for a type.