Enum ReductionType

pub enum ReductionType {
    Accumulable,
    Hierarchical,
    Basic,
}

This enum represents the three potential types of aggregations.

Variants

Accumulable

Accumulable functions can be subtracted from (are invertible), and associative. We can compute these results by moving some data to the diff field under arbitrary changes to inputs. Examples include sum or count.

Hierarchical

Hierarchical functions are associative, which means we can split up the work of computing them across subsets. Note that hierarchical reductions should also reduce the data in some way, as otherwise rendering them hierarchically is not worth it. Examples include min or max.

Basic

Basic, for lack of a better word, are functions that are neither accumulable nor hierarchical. Examples include jsonb_agg.

Trait Implementations

impl Clone for ReductionType

fn clone(&self) -> ReductionType

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Columnation for ReductionType

type InnerRegion = CopyRegion<ReductionType>

The type of region capable of absorbing allocations owned by the Self type. Note: not allocations of Self, but of the things that it owns.

impl Debug for ReductionType

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ReductionType

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Hash for ReductionType

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for ReductionType

fn cmp(&self, other: &ReductionType) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for ReductionType

fn eq(&self, other: &ReductionType) -> 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 PartialOrd for ReductionType

fn partial_cmp(&self, other: &ReductionType) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for ReductionType

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl TryFrom<&ReducePlan> for ReductionType

type Error = ()

The type returned in the event of a conversion error.

fn try_from(plan: &ReducePlan) -> Result<Self, Self::Error>

Performs the conversion.

impl Copy for ReductionType

impl Eq for ReductionType

impl StructuralPartialEq for ReductionType