Enum NdvFallback 

pub enum NdvFallback {
    Max,
    Sum,
}

Fallback to use when NDV overlap can not be estimated from column bounds.

Variants

Max

Use the larger input NDV. This is the conservative default for related fragments such as files from the same table.

Sum

Sum the input NDVs. This is a conservative upper bound for independent inputs such as UNION ALL.

Trait Implementations

impl Clone for NdvFallback

fn clone(&self) -> NdvFallback

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for NdvFallback

impl Debug for NdvFallback

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

Formats the value using the given formatter.

impl Default for NdvFallback

fn default() -> NdvFallback

Returns the “default value” for a type.

impl Eq for NdvFallback

impl PartialEq for NdvFallback

fn eq(&self, other: &NdvFallback) -> 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 NdvFallback