Package org.apache.wayang.basic.operators

Class ReduceByOperator<Type,Key>

java.lang.Object

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

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

org.apache.wayang.basic.operators.ReduceByOperator<Type,Key>

All Implemented Interfaces:

Serializable, ActualOperator, ElementaryOperator, Operator

Direct Known Subclasses:

FlinkReduceByOperator, JavaReduceByOperator, SparkReduceByOperator

public class ReduceByOperator<Type,Key>
extends UnaryToUnaryOperator<Type,Type>

This operator groups the elements of a data set and aggregates the groups.

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

Modifier and Type	Field	Description
protected final TransformationDescriptor<Type,Key>	keyDescriptor
protected final ReduceDescriptor<Type>	reduceDescriptor

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
ReduceByOperator(ReduceByOperator<Type,Key> that)	Copies an instance (exclusive of broadcasts).
ReduceByOperator(FunctionDescriptor.SerializableFunction<Type,Key> keyFunction, FunctionDescriptor.SerializableBinaryOperator<Type> reduceDescriptor, Class<Key> keyClass, Class<Type> typeClass)	Creates a new instance.
ReduceByOperator(TransformationDescriptor<Type,Key> keyDescriptor, ReduceDescriptor<Type> reduceDescriptor)	Creates a new instance.
ReduceByOperator(TransformationDescriptor<Type,Key> keyDescriptor, ReduceDescriptor<Type> reduceDescriptor, DataSetType<Type> type)	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.
TransformationDescriptor<Type,Key>	getKeyDescriptor()
ReduceDescriptor<Type>	getReduceDescriptor()
DataSetType<Type>	getType()

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

Field Details

keyDescriptor

protected final TransformationDescriptor<Type,Key> keyDescriptor

reduceDescriptor

protected final ReduceDescriptor<Type> reduceDescriptor

Constructor Details

ReduceByOperator

public ReduceByOperator(FunctionDescriptor.SerializableFunction<Type,Key> keyFunction,
 FunctionDescriptor.SerializableBinaryOperator<Type> reduceDescriptor,
 Class<Key> keyClass,
 Class<Type> typeClass)

Creates a new instance.

ReduceByOperator

public ReduceByOperator(TransformationDescriptor<Type,Key> keyDescriptor,
 ReduceDescriptor<Type> reduceDescriptor)

Creates a new instance.

Parameters:

keyDescriptor - describes how to extract the key from data units

reduceDescriptor - describes the reduction to be performed on the elements

ReduceByOperator

public ReduceByOperator(TransformationDescriptor<Type,Key> keyDescriptor,
 ReduceDescriptor<Type> reduceDescriptor,
 DataSetType<Type> type)

Creates a new instance.

Parameters:

keyDescriptor - describes how to extract the key from data units

reduceDescriptor - describes the reduction to be performed on the elements

type - type of the reduce elements (i.e., type of UnaryToUnaryOperator.getInput() and UnaryToUnaryOperator.getOutput())

ReduceByOperator

public ReduceByOperator(ReduceByOperator<Type,Key> that)

Copies an instance (exclusive of broadcasts).

Parameters:

that - that should be copied

Method Details

getType

public DataSetType<Type> getType()

getKeyDescriptor

public TransformationDescriptor<Type,Key> getKeyDescriptor()

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