Struct ColumnStats 

pub struct ColumnStats {
    pub name: String,
    pub ndv: u64,
    pub null_fraction: f64,
    pub min_value: Option<f64>,
    pub max_value: Option<f64>,
}

Column statistics

Fields

name: String

Column name

ndv: u64

Number of distinct values (NDV)

null_fraction: f64

Fraction of NULL values

min_value: Option<f64>

Minimum value (for numeric columns)

max_value: Option<f64>

Maximum value (for numeric columns)

Implementations

impl ColumnStats

pub fn new(name: String) -> ColumnStats

Create new column stats

pub fn with_ndv(self, ndv: u64) -> ColumnStats

Set NDV

pub fn with_null_fraction(self, fraction: f64) -> ColumnStats

Set null fraction

pub fn with_range(self, min: f64, max: f64) -> ColumnStats

Set min/max values

pub fn equality_selectivity(&self) -> f64

Estimate selectivity for equality predicate

pub fn range_selectivity(&self, lower: Option<f64>, upper: Option<f64>) -> f64

Estimate selectivity for range predicate

Trait Implementations

impl Clone for ColumnStats

fn clone(&self) -> ColumnStats

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ColumnStats

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

Formats the value using the given formatter.