com.facebook.presto.spi.plan

Class LimitNode

java.lang.Object

com.facebook.presto.spi.plan.PlanNode

com.facebook.presto.spi.plan.LimitNode

@Immutable
public final class LimitNode
extends PlanNode

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	LimitNode.Step Stages of `LimitNode`: PARTIAL: `LimitNode` is in the distributed plan and generates partial results on local workers.

Constructor Summary

Constructors

Constructor and Description
LimitNode(Optional<SourceLocation> sourceLocation, PlanNodeId id, Optional<PlanNode> statsEquivalentPlanNode, PlanNode source, long count, LimitNode.Step step)
LimitNode(Optional<SourceLocation> sourceLocation, PlanNodeId id, PlanNode source, long count, LimitNode.Step step)

Method Summary

Modifier and Type	Method and Description
<R,C> R	accept(PlanVisitor<R,C> visitor, C context) A visitor pattern interface to operate on IR.
PlanNode	assignStatsEquivalentPlanNode(Optional<PlanNode> statsEquivalentPlanNode) Assigns statsEquivalentPlanNode to the plan node
LogicalProperties	computeLogicalProperties(LogicalPropertiesProvider logicalPropertiesProvider) Logical properties are a function of source properties and the operation performed by the plan node
long	getCount() Get the limit `N` number of results to return.
List<VariableReferenceExpression>	getOutputVariables() The output from the upstream PlanNodes.
PlanNode	getSource() LimitNode only expects a single upstream PlanNode.
List<PlanNode>	getSources() Get the upstream PlanNodes (i.e., children) of the current PlanNode.
LimitNode.Step	getStep()
boolean	isPartial()
PlanNode	replaceChildren(List<PlanNode> newChildren) Alter the upstream PlanNodes of the current PlanNode.

Methods inherited from class com.facebook.presto.spi.plan.PlanNode

getId, getSourceLocation, getStatsEquivalentPlanNode

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LimitNode

public LimitNode(Optional<SourceLocation> sourceLocation,
                 PlanNodeId id,
                 PlanNode source,
                 long count,
                 LimitNode.Step step)

LimitNode

public LimitNode(Optional<SourceLocation> sourceLocation,
                 PlanNodeId id,
                 Optional<PlanNode> statsEquivalentPlanNode,
                 PlanNode source,
                 long count,
                 LimitNode.Step step)

Method Detail

getSources

public List<PlanNode> getSources()

Description copied from class: PlanNode

Get the upstream PlanNodes (i.e., children) of the current PlanNode.

Specified by:

getSources in class PlanNode

getSource

public PlanNode getSource()

LimitNode only expects a single upstream PlanNode.

getCount

public long getCount()

Get the limit `N` number of results to return.

getStep

public LimitNode.Step getStep()

isPartial

public boolean isPartial()

computeLogicalProperties

public LogicalProperties computeLogicalProperties(LogicalPropertiesProvider logicalPropertiesProvider)

Description copied from class: PlanNode

Logical properties are a function of source properties and the operation performed by the plan node

Overrides:

computeLogicalProperties in class PlanNode

getOutputVariables

public List<VariableReferenceExpression> getOutputVariables()

Description copied from class: PlanNode

The output from the upstream PlanNodes. It should serve as the input for the current PlanNode.

Specified by:

getOutputVariables in class PlanNode

accept

public <R,C> R accept(PlanVisitor<R,C> visitor,
                      C context)

Description copied from class: PlanNode

A visitor pattern interface to operate on IR.

Overrides:

accept in class PlanNode

assignStatsEquivalentPlanNode

public PlanNode assignStatsEquivalentPlanNode(Optional<PlanNode> statsEquivalentPlanNode)

Description copied from class: PlanNode

Assigns statsEquivalentPlanNode to the plan node

Specified by:

assignStatsEquivalentPlanNode in class PlanNode

replaceChildren

public PlanNode replaceChildren(List<PlanNode> newChildren)

Description copied from class: PlanNode

Alter the upstream PlanNodes of the current PlanNode.

Specified by:

replaceChildren in class PlanNode