Struct DfUdafAdapter

struct DfUdafAdapter {
    name: String,
    signature: Signature,
    return_type_func: ReturnTypeFunction,
    accumulator: AccumulatorFactoryFunction,
    creator: AggregateFunctionCreatorRef,
}

Fields

name: String

signature: Signature

return_type_func: ReturnTypeFunction

accumulator: AccumulatorFactoryFunction

creator: AggregateFunctionCreatorRef

Trait Implementations

impl AggregateUDFImpl for DfUdafAdapter

fn as_any(&self) -> &dyn Any

Returns this object as an Any trait object

fn name(&self) -> &str

Returns this function’s name

fn signature(&self) -> &Signature

Returns the function’s [Signature] for information about what input types are accepted and the function’s Volatility.

fn return_type(&self, arg_types: &[ArrowDataType]) -> Result<ArrowDataType>

What [DataType] will be returned by this function, given the types of the arguments

fn accumulator( &self, acc_args: AccumulatorArgs<'_>, ) -> Result<Box<dyn Accumulator>>

Return a new [Accumulator] that aggregates values for a specific group during query execution.

fn state_fields(&self, args: StateFieldsArgs<'_>) -> Result<Vec<Field>>

Return the fields used to store the intermediate state of this accumulator.

fn groups_accumulator_supported(&self, _args: AccumulatorArgs<'_>) -> bool

If the aggregate expression has a specialized [GroupsAccumulator] implementation. If this returns true, [Self::create_groups_accumulator] will be called.

fn create_groups_accumulator( &self, _args: AccumulatorArgs<'_>, ) -> Result<Box<dyn GroupsAccumulator>, DataFusionError>

Return a specialized [GroupsAccumulator] that manages state for all groups.

fn aliases(&self) -> &[String]

Returns any aliases (alternate names) for this function.

fn create_sliding_accumulator( &self, args: AccumulatorArgs<'_>, ) -> Result<Box<dyn Accumulator>, DataFusionError>

Sliding accumulator is an alternative accumulator that can be used for window functions. It has retract method to revert the previous update.

fn with_beneficial_ordering( self: Arc<Self>, _beneficial_ordering: bool, ) -> Result<Option<Arc<dyn AggregateUDFImpl>>, DataFusionError>

Sets the indicator whether ordering requirements of the AggregateUDFImpl is satisfied by its input. If this is not the case, UDFs with order sensitivity AggregateOrderSensitivity::Beneficial can still produce the correct result with possibly more work internally.

fn order_sensitivity(&self) -> AggregateOrderSensitivity

Gets the order sensitivity of the UDF. See [AggregateOrderSensitivity] for possible options.

fn simplify( &self, ) -> Option<Box<dyn Fn(AggregateFunction, &dyn SimplifyInfo) -> Result<Expr, DataFusionError>>>

Optionally apply per-UDaF simplification / rewrite rules.

fn reverse_expr(&self) -> ReversedUDAF

Returns the reverse expression of the aggregate function.

fn coerce_types( &self, _arg_types: &[DataType], ) -> Result<Vec<DataType>, DataFusionError>

Coerce arguments of a function call to types that the function can evaluate.

impl Debug for DfUdafAdapter

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

Formats the value using the given formatter.