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: SchemaRef) -> Self

Create a new EmptyExec

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

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

Formats the value using the given formatter.

impl ExecutionPlan for EmptyExec

fn as_any(&self) -> &dyn Any

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) -> SchemaRef

Get the schema for this execution plan

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

Get a list of child execution plans that provide the input for this plan. The returned list will be empty for leaf nodes, 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 operator is sorted, returns Some(keys) with the description of how it was sorted.

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

Returns a new plan where all children were replaced by new plans.

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

creates an iterator

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

Format this ExecutionPlan to f in the specified type.

fn statistics(&self) -> Statistics

Returns the global output statistics for this ExecutionPlan node.

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

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

fn required_input_ordering(&self) -> Vec<Option<&[PhysicalSortExpr]>>

Specifies the ordering requirements for all the children for this operator.

fn relies_on_input_order(&self) -> bool

Returns true if this operator relies on its inputs being produced in a certain order (for example that they are sorted a particular way) for correctness.

fn maintains_input_order(&self) -> bool

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

fn benefits_from_input_partitioning(&self) -> bool

Returns true if this operator would benefit from partitioning its input (and thus from more parallelism). For operators that do very little work the overhead of extra parallelism may outweigh any benefits

fn equivalence_properties(&self) -> EquivalenceProperties

Get the EquivalenceProperties within the plan

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

Return a snapshot of the set of Metrics for this ExecutionPlan.