Struct mz_expr::AggregateExpr

pub struct AggregateExpr {
    pub func: AggregateFunc,
    pub expr: MirScalarExpr,
    pub distinct: bool,
}

Describes an aggregation expression.

Fields

func: AggregateFunc

Names the aggregation function.

expr: MirScalarExpr

An expression which extracts from each row the input to func.

distinct: bool

Should the aggregation be applied only to distinct results in each group.

Implementations

impl AggregateExpr

pub fn typ(&self, column_types: &[ColumnType]) -> ColumnType

Computes the type of this AggregateExpr.

pub fn is_constant(&self) -> bool

Returns whether the expression has a constant result.

pub fn on_unique(&self, input_type: &[ColumnType]) -> MirScalarExpr

Returns an expression that computes self on a group that has exactly one row. Instead of performing a Reduce with self, one can perform a Map with the expression returned by on_unique, which is cheaper. (See ReduceElision.)

fn on_unique_ranking_window_funcs( &self, input_type: &[ColumnType], col_name: &str, ) -> MirScalarExpr

on_unique for ROW_NUMBER, RANK, DENSE_RANK

fn on_unique_lag_lead( lag_lead: &LagLeadType, encoded_args: MirScalarExpr, return_type: ScalarType, ) -> (MirScalarExpr, ColumnName)

on_unique for lag and lead

fn on_unique_first_value_last_value( window_frame: &WindowFrame, arg: MirScalarExpr, return_type: ScalarType, ) -> (MirScalarExpr, ColumnName)

on_unique for first_value and last_value

fn on_unique_window_agg( window_frame: &WindowFrame, arg_expr: MirScalarExpr, input_type: &[ColumnType], return_type: ScalarType, wrapped_aggr: &AggregateFunc, ) -> (MirScalarExpr, ColumnName)

on_unique for window aggregations

pub fn is_count_asterisk(&self) -> bool

Returns whether the expression is COUNT() or not. Note that when we define the count builtin in sql::func, we convert COUNT() to COUNT(true), making it indistinguishable from literal COUNT(true), but we prefer to consider this as the former.

Trait Implementations

impl Arbitrary for AggregateExpr

type Parameters = (<AggregateFunc as Arbitrary>::Parameters, <MirScalarExpr as Arbitrary>::Parameters, <bool as Arbitrary>::Parameters)

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

type Strategy = Map<(<AggregateFunc as Arbitrary>::Strategy, <MirScalarExpr as Arbitrary>::Strategy, <bool as Arbitrary>::Strategy), fn(_: (AggregateFunc, MirScalarExpr, bool)) -> AggregateExpr>

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 AggregateExpr

fn clone(&self) -> AggregateExpr

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for AggregateExpr

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for AggregateExpr

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Hash for AggregateExpr

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 AggregateExpr

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 AggregateExpr

fn cmp(&self, other: &AggregateExpr) -> 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 + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for AggregateExpr

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

fn partial_cmp(&self, other: &AggregateExpr) -> 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 RustType<ProtoAggregateExpr> for AggregateExpr

fn into_proto(&self) -> ProtoAggregateExpr

Convert a Self into a Proto value.

fn from_proto(proto: ProtoAggregateExpr) -> Result<Self, TryFromProtoError>

Consume and convert a Proto back into a Self value.

fn into_proto_owned(self) -> Proto

A zero clone version of Self::into_proto that types can optionally implement, otherwise, the default implementation delegates to Self::into_proto.

impl Serialize for AggregateExpr

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 AggregateExpr

impl StructuralPartialEq for AggregateExpr