Enum JoinInputCharacteristics

pub enum JoinInputCharacteristics {
    V1(JoinInputCharacteristicsV1),
    V2(JoinInputCharacteristicsV2),
}

Characteristics of a join order candidate collection.

A candidate is described by a collection and a key, and may have various liabilities. Primarily, the candidate may risk substantial inflation of records, which is something that concerns us greatly. Additionally, the candidate may be unarranged, and we would prefer candidates that do not require additional memory. Finally, we prefer lower id collections in the interest of consistent tie-breaking. For more characteristics, see comments on individual fields.

This has more than one version. new instantiates the appropriate version based on a feature flag.

Variants

V1(JoinInputCharacteristicsV1)

Old version, with enable_join_prioritize_arranged turned off.

V2(JoinInputCharacteristicsV2)

Newer version, with enable_join_prioritize_arranged turned on.

Implementations

impl JoinInputCharacteristics

pub fn new( unique_key: bool, key_length: usize, arranged: bool, cardinality: Option<usize>, filters: FilterCharacteristics, input: usize, enable_join_prioritize_arranged: bool, ) -> Self

Creates a new instance with the given characteristics.

pub fn explain(&self) -> String

Turns the instance into a String to be printed in EXPLAIN.

pub fn arranged(&self) -> bool

Whether the join input described by self is arranged.

pub fn filters(&mut self) -> &mut FilterCharacteristics

Returns the FilterCharacteristics for the join input described by self.

Trait Implementations

impl Arbitrary for JoinInputCharacteristics

type Parameters = (<JoinInputCharacteristicsV1 as Arbitrary>::Parameters, <JoinInputCharacteristicsV2 as Arbitrary>::Parameters)

The type of parameters that arbitrary_with accepts for configuration of the generated Strategy. Parameters must implement Default.

type Strategy = Union<BoxedStrategy<JoinInputCharacteristics>>

The type of Strategy used to generate values of type Self.

fn arbitrary_with(_top: Self::Parameters) -> Self::Strategy

Generates a Strategy for producing arbitrary values of type the implementing type (Self). The strategy is passed the arguments given in args.

fn arbitrary() -> Self::Strategy

Generates a Strategy for producing arbitrary values of type the implementing type (Self).

impl Clone for JoinInputCharacteristics

fn clone(&self) -> JoinInputCharacteristics

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for JoinInputCharacteristics

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for JoinInputCharacteristics

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Hash for JoinInputCharacteristics

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 MzReflect for JoinInputCharacteristics

fn add_to_reflected_type_info(rti: &mut ReflectedTypeInfo)

Adds names and types of the fields of the struct or enum to rti.

impl Ord for JoinInputCharacteristics

fn cmp(&self, other: &JoinInputCharacteristics) -> 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 JoinInputCharacteristics

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

fn partial_cmp(&self, other: &JoinInputCharacteristics) -> 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 JoinInputCharacteristics

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for JoinInputCharacteristics

impl StructuralPartialEq for JoinInputCharacteristics