Package org.apache.wayang.basic.operators

Class ReduceOperator<Type>

java.lang.Object

org.apache.wayang.core.plan.wayangplan.OperatorBase

org.apache.wayang.core.plan.wayangplan.UnaryToUnaryOperator<Type,Type>

org.apache.wayang.basic.operators.ReduceOperator<Type>

All Implemented Interfaces:

Serializable, ActualOperator, ElementaryOperator, Operator

public class ReduceOperator<Type>
extends UnaryToUnaryOperator<Type,Type>

This operator is context dependent: after a GroupByOperator, it is meant to be a ReduceByOperator; otherwise, it is a GlobalReduceOperator.

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.wayang.core.plan.wayangplan.OperatorBase

OperatorBase.GsonSerializer

Field Summary

Fields inherited from class org.apache.wayang.core.plan.wayangplan.OperatorBase

inputSlots, outputSlots, STANDARD_OPERATOR_ARGS

Fields inherited from interface org.apache.wayang.core.plan.wayangplan.Operator

FIRST_EPOCH

Constructor Summary

Constructors

Constructor	Description
ReduceOperator(FunctionDescriptor.SerializableBinaryOperator<Type> reduceDescriptor, Class<Type> typeClass)	Creates a new instance.
ReduceOperator(ReduceDescriptor<Type> reduceDescriptor, DataSetType<Type> inputType, DataSetType<Type> outputType)	Creates a new instance.

Method Summary

Modifier and Type	Method	Description
Optional<CardinalityEstimator>	createCardinalityEstimator(int outputIndex, Configuration configuration)	Provide a CardinalityEstimator for the OutputSlot at outputIndex.
static <Type> ReduceOperator<Type>	createGroupedReduce(ReduceDescriptor<Type> reduceDescriptor, DataSetType<? extends Iterable<Type>> inputType, DataSetType<Type> outputType)	Deprecated. This method is just a hack that is necessary because of the ambiguous nature of this operator.
ReduceDescriptor<Type>	getReduceDescriptor()

Methods inherited from class org.apache.wayang.core.plan.wayangplan.UnaryToUnaryOperator

getInput, getInputType, getOutput, getOutputType

Methods inherited from class org.apache.wayang.core.plan.wayangplan.OperatorBase

accept, addBroadcastInput, addTargetPlatform, at, collectMappedInputSlots, collectMappedOutputSlots, copy, createCopy, getAllInputs, getAllOutputs, getCardinalityEstimator, getContainer, getEpoch, getName, getOriginal, getSimpleClassName, getTargetPlatforms, isAuxiliary, isSupportingBroadcastInputs, propagateInputCardinality, propagateOutputCardinality, setAuxiliary, setCardinalityEstimator, setContainer, setEpoch, setName, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.wayang.core.plan.wayangplan.ActualOperator

accept

Methods inherited from interface org.apache.wayang.core.plan.wayangplan.ElementaryOperator

getCardinalityEstimator, isAuxiliary, setAuxiliary, setCardinalityEstimator

Methods inherited from interface org.apache.wayang.core.plan.wayangplan.Operator

addBroadcastInput, addTargetPlatform, broadcastTo, broadcastTo, collectMappedInputSlots, collectMappedOutputSlots, connectTo, connectTo, getAllInputs, getAllOutputs, getCardinalityPusher, getContainer, getEffectiveOccupant, getEffectiveOccupant, getEpoch, getEstimationContextProperties, getForwards, getInnermostLoop, getInput, getInput, getLoopStack, getName, getNumBroadcastInputs, getNumInputs, getNumOutputs, getNumRegularInputs, getOuterInputSlot, getOutermostInputSlot, getOutermostOutputSlots, getOutput, getOutput, getParent, getTargetPlatforms, isAlternative, isConversion, isElementary, isExecutionOperator, isFeedbackInput, isFeedforwardOutput, isLoopHead, isLoopSubplan, isOwnerOf, isReading, isSink, isSource, isSubplan, isSupportingBroadcastInputs, isUnconnected, propagateInputCardinality, propagateOutputCardinality, propagateOutputCardinality, replaceWith, setContainer, setEpoch, setInput, setName, setOutput

Constructor Details

ReduceOperator

public ReduceOperator(ReduceDescriptor<Type> reduceDescriptor,
 DataSetType<Type> inputType,
 DataSetType<Type> outputType)

Creates a new instance.

Parameters:

reduceDescriptor - describes the reduction to be performed by this operator

ReduceOperator

public ReduceOperator(FunctionDescriptor.SerializableBinaryOperator<Type> reduceDescriptor,
 Class<Type> typeClass)

Creates a new instance.

Parameters:

reduceDescriptor - describes the reduction to be performed by this operator

Method Details

createGroupedReduce

public static <Type> ReduceOperator<Type> createGroupedReduce(ReduceDescriptor<Type> reduceDescriptor,
 DataSetType<? extends Iterable<Type>> inputType,
 DataSetType<Type> outputType)

Deprecated.

This method is just a hack that is necessary because of the ambiguous nature of this operator.

getReduceDescriptor

public ReduceDescriptor<Type> getReduceDescriptor()

createCardinalityEstimator

public Optional<CardinalityEstimator> createCardinalityEstimator(int outputIndex,
 Configuration configuration)

Description copied from interface: ElementaryOperator

Provide a CardinalityEstimator for the OutputSlot at outputIndex.

Parameters:

outputIndex - index of the OutputSlot for that the CardinalityEstimator is requested

configuration - if the CardinalityEstimator depends on further ones, use this to obtain the latter

Returns:

an Optional that might provide the requested instance