Struct datafusion_physical_expr::expressions::MaxAccumulator

pub struct MaxAccumulator { /* private fields */ }

An accumulator to compute the maximum value

Implementations

impl MaxAccumulator

pub fn try_new(datatype: &DataType) -> Result<Self>

new max accumulator

Trait Implementations

impl Accumulator for MaxAccumulator

fn update_batch(&mut self, values: &[ArrayRef]) -> Result<()>

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

fn merge_batch(&mut self, states: &[ArrayRef]) -> Result<()>

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

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

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 evaluate(&self) -> Result<ScalarValue>

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

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

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

impl Debug for MaxAccumulator

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

Formats the value using the given formatter.