Struct ProjectionExec 

pub struct ProjectionExec { /* private fields */ }

ExecutionPlan for a projection

Computes a set of scalar value expressions for each input row, producing one output row for each input row.

Implementations

impl ProjectionExec

pub fn try_new<I, E>(expr: I, input: Arc<dyn ExecutionPlan>) -> Result<Self>

where I: IntoIterator<Item = E>, E: Into<ProjectionExpr>,

Create a projection on an input

Example:

Create a ProjectionExec to crate SELECT a, a+b AS sum_ab FROM t1:

let schema = schema();
// Create PhysicalExprs
let a = col("a", &schema).unwrap();
let b = col("b", &schema).unwrap();
let a_plus_b = binary(Arc::clone(&a), Operator::Plus, b, &schema).unwrap();
// create ProjectionExec
let proj = ProjectionExec::try_new(
    [
        ProjectionExpr {
            // expr a produces the column named "a"
            expr: a,
            alias: "a".to_string(),
        },
        ProjectionExpr {
            // expr: a + b produces the column named "sum_ab"
            expr: a_plus_b,
            alias: "sum_ab".to_string(),
        },
    ],
    input(),
)
.unwrap();

pub fn try_new_with_schema_metadata<I, E>( expr: I, input: Arc<dyn ExecutionPlan>, projected_schema: &Schema, ) -> Result<Self>

where I: IntoIterator<Item = E>, E: Into<ProjectionExpr>,

Create a projection using field and schema metadata from projected_schema.

Field names, data types, and nullability are still derived from the physical projection expressions and the input plan; only field and schema metadata are taken from projected_schema.

Errors

Returns an error if the projection cannot be applied to the input plan, or if projected_schema has a different number of fields than the projection.

pub fn expr(&self) -> &[ProjectionExpr]

The projection expressions stored as tuples of (expression, output column name)

pub fn projection_expr(&self) -> &ProjectionExprs

The projection expressions as a ProjectionExprs.

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

The input plan

impl ProjectionExec

pub fn try_from_proto( node: &PhysicalPlanNode, ctx: &ExecutionPlanDecodeCtx<'_>, ) -> Result<Arc<dyn ExecutionPlan>>

Available on crate feature proto only.

Reconstruct a ProjectionExec from its protobuf representation.

The exact inverse of ExecutionPlan::try_to_proto: it takes the whole PhysicalPlanNode so every plan’s try_from_proto shares one signature. Child plans and expressions are decoded recursively via the ExecutionPlanDecodeCtx.

Trait Implementations

impl Clone for ProjectionExec

fn clone(&self) -> ProjectionExec

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ProjectionExec

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

Formats the value using the given formatter.

impl DisplayAs for ProjectionExec

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 ProjectionExec

fn properties(&self) -> &Arc<PlanProperties>

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 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 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 apply_expressions( &self, f: &mut dyn FnMut(&Arc<dyn PhysicalExpr>) -> Result<TreeNodeRecursion>, ) -> Result<TreeNodeRecursion>

Apply a closure f to each root expression that this node owns and uses during execution, either by evaluating it or updating it dynamically.

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

Returns a clone of the existing plan with the children replaced, skipping recomputation of plan properties when the options indicate the new children’s properties are unchanged.

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

👎Deprecated since 55.0.0:

Use ExecutionPlan::replace_children with ReplaceChildrenOptions

Deprecated.

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

👎Deprecated since 55.0.0:

Use ExecutionPlan::replace_children with ReplaceChildrenOptions

Deprecated. Implement ExecutionPlan::replace_children instead.

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

Begin execution of partition, returning a Stream of RecordBatches.

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

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

fn child_stats_requests(&self, partition: Option<usize>) -> Vec<ChildStats>

Returns, per child, which statistics the StatisticsContext should resolve before calling Self::statistics_from_inputs.

fn statistics_from_inputs( &self, input_stats: &[Arc<Statistics>], _args: &StatisticsArgs, ) -> Result<Arc<Statistics>>

Returns statistics for a specific partition of this ExecutionPlan node, given pre-computed child statistics.

fn supports_limit_pushdown(&self) -> bool

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

fn cardinality_effect(&self) -> CardinalityEffect

Gets the effect on cardinality, if known

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 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.

fn try_pushdown_sort( &self, order: &[PhysicalSortExpr], ) -> Result<SortOrderPushdownResult<Arc<dyn ExecutionPlan>>>

Try to push down sort ordering requirements to this node.

fn with_preserve_order( &self, preserve_order: bool, ) -> Option<Arc<dyn ExecutionPlan>>

Returns a variant of this ExecutionPlan that is aware of order-sensitivity.

fn try_to_proto( &self, ctx: &ExecutionPlanEncodeCtx<'_>, ) -> Result<Option<PhysicalPlanNode>>

Available on crate feature proto only.

Serialize this plan to its protobuf representation, if it knows how.

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 downcast_delegate(&self) -> Option<&dyn ExecutionPlan>

Returns the plan that provides this plan’s public ExecutionPlan downcast identity.

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 dynamic_expressions_produced(&self) -> Vec<Arc<dyn PhysicalExpr>>

Returns the dynamic expressions produced by this plan node.

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

👎Deprecated since 55.0.0:

Use input_distribution_requirements

Specifies simple per-child input distribution requirements.

fn input_distribution_requirements(&self) -> InputDistributionRequirements

Specifies the input distribution requirements for this plan.

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

👎Deprecated since 55.0.0:

Use StatisticsContext::compute instead

Returns statistics for a specific partition of this ExecutionPlan node.

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 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.