Struct ColumnStatistics 

pub struct ColumnStatistics {
    pub name: String,
    pub distinct_count: usize,
    pub null_count: usize,
    pub min_value: Option<Literal>,
    pub max_value: Option<Literal>,
}

Column statistics.

Fields

name: String

Column name.

distinct_count: usize

Number of distinct values.

null_count: usize

Number of null values.

min_value: Option<Literal>

Minimum value (if available).

max_value: Option<Literal>

Maximum value (if available).

Implementations

impl ColumnStatistics

pub fn new(name: String, distinct_count: usize, null_count: usize) -> Self

Create new column statistics.

pub fn equality_selectivity(&self, _total_rows: usize) -> f64

Selectivity for equality predicate.

pub fn range_selectivity(&self, low: &Literal, high: &Literal) -> f64

Selectivity for range predicate.

Trait Implementations

impl Clone for ColumnStatistics

fn clone(&self) -> ColumnStatistics

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ColumnStatistics

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ColumnStatistics

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for ColumnStatistics

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.