Struct ExprBoundaries

pub struct ExprBoundaries {
    pub column: Column,
    pub interval: Option<Interval>,
    pub distinct_count: Precision<usize>,
}

Represents the boundaries (e.g. min and max values) of a particular column

This is used range analysis of expressions, to determine if the expression limits the value of particular columns (e.g. analyzing an expression such as time < 50 would result in a boundary interval for time having a max value of 50).

Fields

column: Column

interval: Option<Interval>

Minimum and maximum values this expression can have. A None value indicates that evaluating the given column results in an empty set. For example, if the column a has values in the range [10, 20], and there is a filter asserting that a > 50, then the resulting interval range of a will be None.

distinct_count: Precision<usize>

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

Implementations

impl ExprBoundaries

pub fn try_from_column( schema: &Schema, col_stats: &ColumnStatistics, col_index: usize, ) -> Result<Self>

Create a new ExprBoundaries object from column level statistics.

pub fn try_new_unbounded(schema: &Schema) -> Result<Vec<Self>>

Create ExprBoundaries that represent no known bounds for all the columns in schema

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 for ExprBoundaries

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

Tests for self and other values to be equal, and is used by ==.

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

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

impl StructuralPartialEq for ExprBoundaries