Struct datafusion::physical_plan::empty::EmptyExec

pub struct EmptyExec { /* private fields */ }

Execution plan for empty relation (produces no rows)

Implementations

impl EmptyExec

pub fn new(produce_one_row: bool, schema: Arc<Schema>) -> EmptyExec

Create a new EmptyExec

pub fn with_partitions(self, partitions: usize) -> EmptyExec

Create a new EmptyExec with specified partition number

pub fn produce_one_row(&self) -> bool

Specifies whether this exec produces a row or not

Trait Implementations

impl Debug for EmptyExec

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

Formats the value using the given formatter.

impl DisplayAs for EmptyExec

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

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

impl ExecutionPlan for EmptyExec

fn as_any(&self) -> &(dyn Any + 'static)

Return a reference to Any that can be used for downcasting

fn output_partitioning(&self) -> Partitioning

Get the output partitioning of this plan

fn schema(&self) -> Arc<Schema>

Get the schema for this execution plan

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 output_ordering(&self) -> Option<&[PhysicalSortExpr]>

If the output of this ExecutionPlan within each partition is sorted, returns Some(keys) with the description of how it was sorted.

fn with_new_children( self: Arc<EmptyExec>, _: Vec<Arc<dyn ExecutionPlan>> ) -> Result<Arc<dyn ExecutionPlan>, DataFusionError>

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

fn execute( &self, partition: usize, context: Arc<TaskContext> ) -> Result<Pin<Box<dyn RecordBatchStream<Item = Result<RecordBatch, DataFusionError>> + Send>>, DataFusionError>

Begin execution of partition, returning a Stream of RecordBatches.

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

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

fn unbounded_output(&self, _children: &[bool]) -> Result<bool, DataFusionError>

Specifies whether this plan generates an infinite stream of records. If the plan does not support pipelining, but its input(s) are infinite, returns an error to indicate this.

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<Vec<PhysicalSortRequirement>>>

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

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 equivalence_properties(&self) -> EquivalenceProperties

Get the EquivalenceProperties within the plan

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

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

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

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