Struct datafusion::physical_plan::joins::NestedLoopJoinExec

pub struct NestedLoopJoinExec { /* private fields */ }

NestedLoopJoinExec executes partitions in parallel. One input will be collected to a single partition, call it inner-table. The other side of the input is treated as outer-table, and the output Partitioning is from it. Giving an output partition number x, the execution will be:

for outer-table-batch in outer-table-partition-x
    check-join(outer-table-batch, inner-table-data)

One of the inputs will become inner table, and it is decided by the join type. Following is the relation table:

JoinType	Distribution (left, right)	Inner-table
Inner/Left/LeftSemi/LeftAnti	(UnspecifiedDistribution, SinglePartition)	right
Right/RightSemi/RightAnti/Full	(SinglePartition, UnspecifiedDistribution)	left
Full	(SinglePartition, SinglePartition)	left

Implementations

impl NestedLoopJoinExec

pub fn try_new( left: Arc<dyn ExecutionPlan>, right: Arc<dyn ExecutionPlan>, filter: Option<JoinFilter>, join_type: &JoinType ) -> Result<Self>

Try to create a nwe NestedLoopJoinExec

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

left side

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

right side

pub fn filter(&self) -> Option<&JoinFilter>

Filters applied before join output

pub fn join_type(&self) -> &JoinType

How the join is performed

Trait Implementations

impl Debug for NestedLoopJoinExec

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

Formats the value using the given formatter.

impl DisplayAs for NestedLoopJoinExec

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 NestedLoopJoinExec

fn as_any(&self) -> &dyn Any

Returns the execution plan as Any so that it can be downcast to a specific implementation.

fn schema(&self) -> SchemaRef

Get the schema for this execution plan

fn output_partitioning(&self) -> Partitioning

Specifies the output partitioning scheme of this plan

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

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

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 equivalence_properties(&self) -> EquivalenceProperties

Get the EquivalenceProperties within the 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 with_new_children( self: Arc<Self>, children: 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 metrics(&self) -> Option<MetricsSet>

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

fn statistics(&self) -> Statistics

Returns the global output statistics for this ExecutionPlan node.

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

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_ordering(&self) -> Vec<Option<Vec<PhysicalSortRequirement>>>

Specifies the ordering requirements for all of the children For each child, it’s the local ordering requirement within each partition rather than the global ordering

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

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

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

Specifies whether the operator benefits from increased parallelization at its input for each child. If set to true, this indicates that the operator would benefit from partitioning its corresponding child (and thus from more parallelism). For operators that do very little work the overhead of extra parallelism may outweigh any benefits

fn ordering_equivalence_properties(&self) -> OrderingEquivalenceProperties

Get the OrderingEquivalenceProperties within the plan

fn file_scan_config(&self) -> Option<&FileScanConfig>

Returns the FileScanConfig in case this is a data source scanning execution plan or None otherwise.