Struct datafusion_physical_expr::ExprBoundaries

pub struct ExprBoundaries {
    pub min_value: ScalarValue,
    pub max_value: ScalarValue,
    pub distinct_count: Option<usize>,
    pub selectivity: Option<f64>,
}

Represents the boundaries of the resulting value from a physical expression, if it were to be an expression, if it were to be evaluated.

Fields

min_value: ScalarValue

Minimum value this expression’s result can have.

max_value: ScalarValue

Maximum value this expression’s result can have.

distinct_count: Option<usize>

Maximum number of distinct values this expression can produce, if known.

selectivity: Option<f64>

The estimated percantage of rows that this expression would select, if it were to be used as a boolean predicate on a filter. The value will be between 0.0 (selects nothing) and 1.0 (selects everything).

Implementations

impl ExprBoundaries

pub fn new(
    min_value: ScalarValue,
    max_value: ScalarValue,
    distinct_count: Option<usize>
) -> Self

Create a new ExprBoundaries.

pub fn new_with_selectivity(
    min_value: ScalarValue,
    max_value: ScalarValue,
    distinct_count: Option<usize>,
    selectivity: Option<f64>
) -> Self

Create a new ExprBoundaries with a selectivity value.

pub fn from_column(column: &ColumnStatistics) -> Option<Self>

Create a new ExprBoundaries from a column level statistics.

pub fn reduce(&self) -> Option<ScalarValue>

Try to reduce the boundaries into a single scalar value, if possible.

Trait Implementations

impl Clone for ExprBoundaries

fn clone(&self) -> ExprBoundaries

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ExprBoundaries

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

Formats the value using the given formatter.

impl PartialEq<ExprBoundaries> for ExprBoundaries

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for ExprBoundaries