Struct CoalesceBatchesExec 

pub struct CoalesceBatchesExec {
    input: Arc<dyn ExecutionPlan>,
    target_batch_size: usize,
    fetch: Option<usize>,
    metrics: ExecutionPlanMetricsSet,
    cache: PlanProperties,
}

CoalesceBatchesExec combines small batches into larger batches for more efficient vectorized processing by later operators.

The operator buffers batches until it collects target_batch_size rows and then emits a single concatenated batch. When only a limited number of rows are necessary (specified by the fetch parameter), the operator will stop buffering and returns the final batch once the number of collected rows reaches the fetch value.

See LimitedBatchCoalescer for more information

Fields

input: Arc<dyn ExecutionPlan>

The input plan

target_batch_size: usize

Minimum number of rows for coalescing batches

fetch: Option<usize>

Maximum number of rows to fetch, None means fetching all rows

metrics: ExecutionPlanMetricsSet

Execution metrics

cache: PlanProperties

Implementations

impl CoalesceBatchesExec

pub fn new(input: Arc<dyn ExecutionPlan>, target_batch_size: usize) -> Self

Create a new CoalesceBatchesExec

pub fn with_fetch(self, fetch: Option<usize>) -> Self

Update fetch with the argument

pub fn input(&self) -> &Arc<dyn ExecutionPlan>

The input plan

pub fn target_batch_size(&self) -> usize

Minimum number of rows for coalesces batches

fn compute_properties(input: &Arc<dyn ExecutionPlan>) -> PlanProperties

This function creates the cache object that stores the plan properties such as schema, equivalence properties, ordering, partitioning, etc.

Trait Implementations

impl Clone for CoalesceBatchesExec

fn clone(&self) -> CoalesceBatchesExec

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CoalesceBatchesExec

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

Formats the value using the given formatter.

impl DisplayAs for CoalesceBatchesExec

fn fmt_as(&self, t: DisplayFormatType, f: &mut Formatter<'_>) -> Result

Format according to DisplayFormatType, used when verbose representation looks different from the default one

impl ExecutionPlan for CoalesceBatchesExec

fn as_any(&self) -> &dyn Any

Return a reference to Any that can be used for downcasting

fn name(&self) -> &'static str

Short name for the ExecutionPlan, such as ‘DataSourceExec’.

fn properties(&self) -> &PlanProperties

Return properties of the output of the ExecutionPlan, such as output ordering(s), partitioning information etc.

fn children(&self) -> Vec<&Arc<dyn ExecutionPlan>>

Get a list of children ExecutionPlans that act as inputs to this plan. The returned list will be empty for leaf nodes such as scans, will contain a single value for unary nodes, or two values for binary nodes (such as joins).

fn maintains_input_order(&self) -> Vec<bool>

Returns false if this ExecutionPlan’s implementation may reorder rows within or between partitions.

fn benefits_from_input_partitioning(&self) -> Vec<bool>

Specifies whether the ExecutionPlan benefits from increased parallelization at its input for each child.

fn with_new_children( self: Arc<Self>, children: Vec<Arc<dyn ExecutionPlan>>, ) -> Result<Arc<dyn ExecutionPlan>>

Returns a new ExecutionPlan where all existing children were replaced by the children, in order

fn execute( &self, partition: usize, context: Arc<TaskContext>, ) -> Result<SendableRecordBatchStream>

Begin execution of partition, returning a Stream of [RecordBatch]es.

fn metrics(&self) -> Option<MetricsSet>

Return a snapshot of the set of Metrics for this ExecutionPlan. If no Metrics are available, return None.

fn statistics(&self) -> Result<Statistics>

👎Deprecated since 48.0.0: Use partition_statistics method instead

Returns statistics for this ExecutionPlan node. If statistics are not available, should return Statistics::new_unknown (the default), not an error.

fn partition_statistics(&self, partition: Option<usize>) -> Result<Statistics>

Returns statistics for a specific partition of this ExecutionPlan node. If statistics are not available, should return Statistics::new_unknown (the default), not an error. If partition is None, it returns statistics for the entire plan.

fn with_fetch(&self, limit: Option<usize>) -> Option<Arc<dyn ExecutionPlan>>

Returns a fetching variant of this ExecutionPlan node, if it supports fetch limits. Returns None otherwise.

fn fetch(&self) -> Option<usize>

Gets the fetch count for the operator, None means there is no fetch.

fn cardinality_effect(&self) -> CardinalityEffect

Gets the effect on cardinality, if known

fn gather_filters_for_pushdown( &self, _phase: FilterPushdownPhase, parent_filters: Vec<Arc<dyn PhysicalExpr>>, _config: &ConfigOptions, ) -> Result<FilterDescription>

Collect filters that this node can push down to its children. Filters that are being pushed down from parents are passed in, and the node may generate additional filters to push down. For example, given the plan FilterExec -> HashJoinExec -> DataSourceExec, what will happen is that we recurse down the plan calling ExecutionPlan::gather_filters_for_pushdown:

fn handle_child_pushdown_result( &self, _phase: FilterPushdownPhase, child_pushdown_result: ChildPushdownResult, _config: &ConfigOptions, ) -> Result<FilterPushdownPropagation<Arc<dyn ExecutionPlan>>>

Handle the result of a child pushdown. This method is called as we recurse back up the plan tree after pushing filters down to child nodes via ExecutionPlan::gather_filters_for_pushdown. It allows the current node to process the results of filter pushdown from its children, deciding whether to absorb filters, modify the plan, or pass filters back up to its parent.

fn static_name() -> &'static str

where Self: Sized,

Short name for the ExecutionPlan, such as ‘DataSourceExec’. Like name but can be called without an instance.

fn schema(&self) -> SchemaRef

Get the schema for this execution plan

fn check_invariants(&self, check: InvariantLevel) -> Result<()>

Returns an error if this individual node does not conform to its invariants. These invariants are typically only checked in debug mode.

fn required_input_distribution(&self) -> Vec<Distribution>

Specifies the data distribution requirements for all the children for this ExecutionPlan, By default it’s [Distribution::UnspecifiedDistribution] for each child,

fn required_input_ordering(&self) -> Vec<Option<OrderingRequirements>>

Specifies the ordering required for all of the children of this ExecutionPlan.

fn reset_state(self: Arc<Self>) -> Result<Arc<dyn ExecutionPlan>>

Reset any internal state within this ExecutionPlan.

fn repartitioned( &self, _target_partitions: usize, _config: &ConfigOptions, ) -> Result<Option<Arc<dyn ExecutionPlan>>>

If supported, attempt to increase the partitioning of this ExecutionPlan to produce target_partitions partitions.

fn supports_limit_pushdown(&self) -> bool

Returns true if a limit can be safely pushed down through this ExecutionPlan node.

fn try_swapping_with_projection( &self, _projection: &ProjectionExec, ) -> Result<Option<Arc<dyn ExecutionPlan>>>

Attempts to push down the given projection into the input of this ExecutionPlan.

fn with_new_state( &self, _state: Arc<dyn Any + Send + Sync>, ) -> Option<Arc<dyn ExecutionPlan>>

Injects arbitrary run-time state into this execution plan, returning a new plan instance that incorporates that state if it is relevant to the concrete node implementation.