Struct PlanSignature 

pub struct PlanSignature { /* private fields */ }

Builds a GraphStats::plan_signature: a hash of every input the planner reads from the stats, with cardinalities coarsened to power-of-two buckets. Backends feed it the same items GraphStats holds, in a deterministic order, without building the maps.

Implementations

impl PlanSignature

pub fn new() -> Self

pub fn bucket(count: usize) -> u32

Bucket of a cardinality: 0 for 0, else its bit length (1, 2-3, 4-7, …). Cost estimates within one bucket are within a factor of two of each other.

pub fn totals(&mut self, nodes: usize, relationships: usize)

pub fn label(&mut self, label: &str, nodes: usize)

A label present in the stats (even with no nodes left: an absent label and an empty one estimate differently).

pub fn relationship_type(&mut self, rel_type: &str, relationships: usize)

pub fn node_distinct(&mut self, label: &str, property: &str, distinct: usize)

pub fn relationship_distinct( &mut self, rel_type: &str, property: &str, distinct: usize, )

pub fn index( &mut self, entity: StoredIndexEntity, kind: StoredIndexKind, label: &str, property: &str, )

An online range / text / point / vector index scope, as the *_indexes sets of GraphStats hold them.

pub fn list_elements( &mut self, entity: StoredIndexEntity, label: &str, property: &str, stats: ListElementStats, )

A RANGE index scope holding list elements, by the entities one element seek finds on average.

pub fn finish(&self) -> u64

Trait Implementations

impl Default for PlanSignature

fn default() -> Self

Returns the “default value” for a type.