Package org.apache.wayang.basic.operators

Class GroupByOperator<Input,Key>

java.lang.Object

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

org.apache.wayang.core.plan.wayangplan.UnaryToUnaryOperator<Input,Iterable<Input>>

org.apache.wayang.basic.operators.GroupByOperator<Input,Key>

All Implemented Interfaces:

Serializable, ActualOperator, ElementaryOperator, Operator

Direct Known Subclasses:

FlinkGroupByOperator

public class GroupByOperator<Input,Key>
extends UnaryToUnaryOperator<Input,Iterable<Input>>

This is the auxiliary GroupBy operator, i.e., it behaves differently depending on its context. If it is followed by a ReduceOperator (and akin), it turns that one into a ReduceByOperator. Otherwise, it corresponds to a MaterializedGroupByOperator.

See Also:

• MaterializedGroupByOperator
• ReduceOperator
• 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<Input,Key>	keyDescriptor

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
GroupByOperator(GroupByOperator<Input,Key> that)
GroupByOperator(FunctionDescriptor.SerializableFunction<Input,Key> keyFunction, Class<Input> typeClass, Class<Key> keyClass)	Creates a new instance.
GroupByOperator(TransformationDescriptor<Input,Key> keyDescriptor)	Creates a new instance.
GroupByOperator(TransformationDescriptor<Input,Key> keyDescriptor, DataSetType<Input> inputType, DataSetType<Iterable<Input>> outputType)	Creates a new instance.

Method Summary

Modifier and Type	Method	Description
TransformationDescriptor<Input,Key>	getKeyDescriptor()

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

createCardinalityEstimator, 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<Input,Key> keyDescriptor

Constructor Details

GroupByOperator

public GroupByOperator(FunctionDescriptor.SerializableFunction<Input,Key> keyFunction,
 Class<Input> typeClass,
 Class<Key> keyClass)

Creates a new instance.

Parameters:

keyFunction - describes how to extract the key from data units

typeClass - class of the data quanta to be grouped

keyClass - class of the extracted keys

GroupByOperator

public GroupByOperator(TransformationDescriptor<Input,Key> keyDescriptor)

Creates a new instance.

Parameters:

keyDescriptor - describes the key w.r.t. to the processed data units

GroupByOperator

public GroupByOperator(TransformationDescriptor<Input,Key> keyDescriptor,
 DataSetType<Input> inputType,
 DataSetType<Iterable<Input>> outputType)

Creates a new instance.

Parameters:

keyDescriptor - describes the key w.r.t. to the processed data units

inputType - class of the input types (i.e., type of UnaryToUnaryOperator.getInput()

outputType - class of the output types (i.e., type of UnaryToUnaryOperator.getOutput()

GroupByOperator

public GroupByOperator(GroupByOperator<Input,Key> that)

Method Details

getKeyDescriptor

public TransformationDescriptor<Input,Key> getKeyDescriptor()