Struct GraphStats 

pub struct GraphStats {

    pub node_count: usize,
    pub relationship_count: usize,
    pub nodes_by_label: BTreeMap<String, usize>,
    pub relationships_by_type: BTreeMap<String, usize>,
    pub node_distinct_values: Arc<DistinctValues>,
    pub relationship_distinct_values: Arc<DistinctValues>,
    pub node_range_indexes: BTreeSet<(String, String)>,
    pub relationship_range_indexes: BTreeSet<(String, String)>,
    pub node_text_indexes: BTreeSet<(String, String)>,
    pub relationship_text_indexes: BTreeSet<(String, String)>,
    pub node_point_indexes: BTreeSet<(String, String)>,
    pub relationship_point_indexes: BTreeSet<(String, String)>,
    pub node_vector_indexes: BTreeSet<(String, String)>,
    pub relationship_vector_indexes: BTreeSet<(String, String)>,
    pub node_list_elements: BTreeMap<(String, String), ListElementStats>,
    pub relationship_list_elements: BTreeMap<(String, String), ListElementStats>,
}

Snapshot of graph cardinality. Populated by the storage backend (see [super::InMemoryGraph::stats]).

Fields

node_count: usize

Total live node count.

relationship_count: usize

Total live relationship count.

nodes_by_label: BTreeMap<String, usize>

Per-label node count. nodes_by_label[label].len().

relationships_by_type: BTreeMap<String, usize>

Per-rel-type relationship count. relationships_by_type[type].len().

node_distinct_values: Arc<DistinctValues>

Per-(label, property) approximate distinct value count, for every property key that a live node with that label carries, indexed or not. Estimated from a distinct-value sketch kept on every write (see memory::distinct_stats): a function of the live data alone, so a restarted process, the writer and a process with a different lookup history get the same numbers. Absent only for keys no node of the label has (or whose values the hash index can’t key: NaN, durations, points, vectors). Shared: the store reuses one map while the estimates don’t change.

relationship_distinct_values: Arc<DistinctValues>

Per-(relationship type, property) distinct value count; as above.

node_range_indexes: BTreeSet<(String, String)>

Online catalog-backed range indexes by (label_or_type, property).

relationship_range_indexes: BTreeSet<(String, String)>

node_text_indexes: BTreeSet<(String, String)>

Online catalog-backed text indexes by (label_or_type, property).

relationship_text_indexes: BTreeSet<(String, String)>

node_point_indexes: BTreeSet<(String, String)>

Online catalog-backed point indexes by (label_or_type, property).

relationship_point_indexes: BTreeSet<(String, String)>

node_vector_indexes: BTreeSet<(String, String)>

Online catalog-backed vector indexes by (label_or_type, property). Tracked alongside the other index scopes so the optimizer / planner can see them in stats fingerprints, though kNN currently goes through a flat per-query scan rather than a dedicated structure.

relationship_vector_indexes: BTreeSet<(String, String)>

node_list_elements: BTreeMap<(String, String), ListElementStats>

List elements held by the RANGE index scopes whose property holds lists, by (label_or_type, property): what an element seek ($x IN n.list) is costed from. Exact counts, kept on every write.

relationship_list_elements: BTreeMap<(String, String), ListElementStats>

Implementations

impl GraphStats

pub fn estimate_node_property_equality( &self, label: &str, property: &str, ) -> Option<u64>

Selectivity of an equality predicate label:prop = value. Returns Some(rows) when we have enough info to answer; None when the optimizer should fall back to its conservative default.

pub fn estimate_node_list_element( &self, label: &str, property: &str, ) -> Option<u64>

Rows an element seek $x IN label.property finds, from the RANGE index on the pair: the average entities per element, or 0 when the indexed values hold no list element. None without the index.

pub fn estimate_relationship_list_element( &self, rel_type: &str, property: &str, ) -> Option<u64>

Mirror of Self::estimate_node_list_element for relationships.

pub fn label_count(&self, label: &str) -> Option<u64>

pub fn relationship_type_count(&self, rel_type: &str) -> Option<u64>

pub fn fingerprint(&self) -> u64

pub fn plan_signature(&self) -> u64

Hash of what the planner reads from these stats, with every cardinality coarsened to a power-of-two bucket (see PlanSignature). Two stats with the same signature have the same labels, types, counted keys and online index scopes, and counts within a factor of two: a plan made for one is a sound and reasonable plan for the other. Plans never depend on stats for correctness, only for cost.

pub fn has_node_range_index(&self, label: &str, property: &str) -> bool

pub fn has_node_text_index(&self, label: &str, property: &str) -> bool

pub fn has_node_point_index(&self, label: &str, property: &str) -> bool

pub fn has_relationship_range_index( &self, rel_type: &str, property: &str, ) -> bool

pub fn has_relationship_text_index( &self, rel_type: &str, property: &str, ) -> bool

pub fn has_relationship_point_index( &self, rel_type: &str, property: &str, ) -> bool

pub fn has_node_vector_index(&self, label: &str, property: &str) -> bool

pub fn has_relationship_vector_index( &self, rel_type: &str, property: &str, ) -> bool

Trait Implementations

impl Clone for GraphStats

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for GraphStats

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

Formats the value using the given formatter.

impl Default for GraphStats

fn default() -> Self

Returns the “default value” for a type.

impl Eq for GraphStats

impl PartialEq for GraphStats

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for GraphStats