Struct datafusion::physical_plan::expressions::AvgAccumulator

pub struct AvgAccumulator { /* private fields */ }

An accumulator to compute the average

Implementations

impl AvgAccumulator

pub fn try_new(datatype: &DataType) -> Result<AvgAccumulator, DataFusionError>

Creates a new AvgAccumulator

Trait Implementations

impl Accumulator for AvgAccumulator

fn state(&self) -> Result<Vec<ScalarValue, Global>, DataFusionError>

Returns the partial intermediate state of the accumulator. This partial state is serialied as Arrays and then combined with other partial states from different instances of this accumulator (that ran on different partitions, for example).

fn update_batch( &mut self, values: &[Arc<dyn Array + 'static>] ) -> Result<(), DataFusionError>

Updates the accumulator’s state from a vector of arrays.

fn retract_batch( &mut self, values: &[Arc<dyn Array + 'static>] ) -> Result<(), DataFusionError>

Retracts an update (caused by the given inputs) to accumulator’s state.

fn merge_batch( &mut self, states: &[Arc<dyn Array + 'static>] ) -> Result<(), DataFusionError>

Updates the accumulator’s state from an Array containing one or more intermediate values.

fn evaluate(&self) -> Result<ScalarValue, DataFusionError>

Returns the final aggregate value based on its current state.

fn size(&self) -> usize

Allocated size required for this accumulator, in bytes, including Self. Allocated means that for internal containers such as Vec, the capacity should be used not the len

impl Debug for AvgAccumulator

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

Formats the value using the given formatter.