Struct ColumnStatsSnapshot 

pub struct ColumnStatsSnapshot {
    pub row_count: u64,
    pub null_count: Option<u64>,
    pub distinct_count: Option<u64>,
    pub hll: Option<HyperLogLog>,
    pub min_value: Option<Value>,
    pub max_value: Option<Value>,
}

Immutable point-in-time statistics for one property column of a vertex tag or an edge type.

Fields

row_count: u64

Live row estimate for the owning relation (tag / edge type).

null_count: Option<u64>

Number of null values, when tracked by the storage layer.

distinct_count: Option<u64>

Distinct value count excluding nulls, as an HLL union estimate over available registers. Retained when any contributing table tracks it.

hll: Option<HyperLogLog>

HLL registers backing the distinct estimate when available.

min_value: Option<Value>

Global minimum over non-null values (zone-map bounds are conservative: they only widen after writes, never shrink).

max_value: Option<Value>

Global maximum over non-null values.

Implementations

impl ColumnStatsSnapshot

pub fn has_envelope(&self) -> bool

Whether this snapshot carries any usable bound for selectivity estimation.

pub fn absorb(&mut self, other: &ColumnStatsSnapshot)

Merge other into self so that self covers the union of both snapshots’ rows:

• row counts add up;
• min/max bounds widen using the numeric-aware comparison shared with pushed-predicate evaluation;
• null counts sum over the tables that track them (missing tracking is treated as no contribution);
• distinct counts merge HLL registers into a union estimate when both sides carry HLL state; when only numeric estimates exist without registers the merge degrades to None instead of summing (a sum would be a loose upper bound that double-counts overlap).

pub fn set_hll(&mut self, hll: HyperLogLog)

Attach an HLL estimator and refresh the distinct estimate from it.

Trait Implementations

impl Clone for ColumnStatsSnapshot

fn clone(&self) -> ColumnStatsSnapshot

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ColumnStatsSnapshot

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

Formats the value using the given formatter.

impl Default for ColumnStatsSnapshot

fn default() -> ColumnStatsSnapshot

Returns the “default value” for a type.