Struct DistinctMedianAccumulator 

struct DistinctMedianAccumulator<T: ArrowNumericType> {
    data_type: DataType,
    distinct_values: HashSet<Hashable<T::Native>>,
}

The distinct median accumulator accumulates the raw input values as ScalarValues

The intermediate state is represented as a List of scalar values updated by merge_batch and a Vec of ArrayRef that are converted to scalar values in the final evaluation step so that we avoid expensive conversions and allocations during update_batch.

Fields

data_type: DataType

distinct_values: HashSet<Hashable<T::Native>>

Trait Implementations

impl<T: ArrowNumericType> Accumulator for DistinctMedianAccumulator<T>

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

Returns the intermediate state of the accumulator, consuming the intermediate state.

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

Updates the accumulator’s state from its input.

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

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

fn evaluate(&mut self) -> Result<ScalarValue>

Returns the final aggregate value, consuming the internal state.

fn size(&self) -> usize

Returns the allocated size required for this accumulator, in bytes, including Self.

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

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

fn supports_retract_batch(&self) -> bool

Does the accumulator support incrementally updating its value by removing values.

impl<T: ArrowNumericType> Debug for DistinctMedianAccumulator<T>

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

Formats the value using the given formatter.