Struct CountHashGroupAccumulator

pub struct CountHashGroupAccumulator {
    distinct_sets: Vec<HashSet<u64, RandomState>>,
    random_state: RandomState,
    batch_hashes: Vec<u64>,
}

GroupsAccumulator for count_hash aggregate function

Fields

distinct_sets: Vec<HashSet<u64, RandomState>>

One HashSet per group to track distinct values

random_state: RandomState

batch_hashes: Vec<u64>

Implementations

impl CountHashGroupAccumulator

pub fn new() -> Self

fn ensure_sets(&mut self, total_num_groups: usize)

Trait Implementations

impl Debug for CountHashGroupAccumulator

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

Formats the value using the given formatter.

impl Default for CountHashGroupAccumulator

fn default() -> Self

Returns the “default value” for a type.

impl GroupsAccumulator for CountHashGroupAccumulator

fn update_batch( &mut self, values: &[ArrayRef], group_indices: &[usize], opt_filter: Option<&BooleanArray>, total_num_groups: usize, ) -> Result<()>

Updates the accumulator’s state from its arguments, encoded as a vector of [ArrayRef]s.

fn evaluate(&mut self, emit_to: EmitTo) -> Result<ArrayRef>

Returns the final aggregate value for each group as a single RecordBatch, resetting the internal state.

fn merge_batch( &mut self, values: &[ArrayRef], group_indices: &[usize], _opt_filter: Option<&BooleanArray>, total_num_groups: usize, ) -> Result<()>

Merges intermediate state (the output from [Self::state]) into this accumulator’s current state.

fn state(&mut self, emit_to: EmitTo) -> Result<Vec<ArrayRef>>

Returns the intermediate aggregate state for this accumulator, used for multi-phase grouping, resetting its internal state.

fn convert_to_state( &self, values: &[ArrayRef], opt_filter: Option<&BooleanArray>, ) -> Result<Vec<ArrayRef>>

Converts an input batch directly to the intermediate aggregate state.

fn supports_convert_to_state(&self) -> bool

Returns true if [Self::convert_to_state] is implemented to support intermediate aggregate state conversion.

fn size(&self) -> usize

Amount of memory used to store the state of this accumulator, in bytes.