Package org.apache.wayang.basic.operators

Class SampleOperator<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.SampleOperator<Type>

All Implemented Interfaces:

Serializable, ActualOperator, ElementaryOperator, Operator

Direct Known Subclasses:

FlinkSampleOperator, JavaRandomSampleOperator, JavaReservoirSampleOperator, SparkBernoulliSampleOperator, SparkRandomPartitionSampleOperator, SparkShufflePartitionSampleOperator

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

A random sample operator randomly selects its inputs from the input slot and pushes that element to the output slot.

See Also:

• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	SampleOperator.Methods

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

OperatorBase.GsonSerializer

Field Summary

Fields

Modifier and Type	Field	Description
protected Long	datasetSize	Size of the dataset to be sampled or 0L if a dataset size is not known.
protected final org.apache.logging.log4j.Logger	logger
protected FunctionDescriptor.SerializableIntUnaryOperator	sampleSizeFunction	This function determines the sample size by the number of iterations.
protected FunctionDescriptor.SerializableLongUnaryOperator	seedFunction	This function optionally determines the seed by the number of iterations.
static final long	UNKNOWN_DATASET_SIZE	Special dataset size that represents "unknown".

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
SampleOperator(Integer sampleSize, DataSetType<Type> type)	Creates a new instance with any sampling method.
SampleOperator(Integer sampleSize, DataSetType<Type> type, SampleOperator.Methods sampleMethod, long seed)	Creates a new instance given the sample size and the seed.
SampleOperator(SampleOperator<Type> that)	Copies an instance (exclusive of broadcasts).
SampleOperator(FunctionDescriptor.SerializableIntUnaryOperator sampleSizeFunction, DataSetType<Type> type)	Creates a new instance with any sampling method.
SampleOperator(FunctionDescriptor.SerializableIntUnaryOperator sampleSizeFunction, DataSetType<Type> type, SampleOperator.Methods sampleMethod)	Creates a new instance given the sample size and the method.
SampleOperator(FunctionDescriptor.SerializableIntUnaryOperator sampleSizeFunction, DataSetType<Type> type, SampleOperator.Methods sampleMethod, long seed)	Creates a new instance given a user-defined sample size.
SampleOperator(FunctionDescriptor.SerializableIntUnaryOperator sampleSizeFunction, DataSetType<Type> type, SampleOperator.Methods sampleMethod, FunctionDescriptor.SerializableLongUnaryOperator seedFunction)	Creates a new instance given user-defined sample size and seed methods.

Method Summary

Modifier and Type	Method	Description
Optional<CardinalityEstimator>	createCardinalityEstimator(int outputIndex, Configuration configuration)	Provide a CardinalityEstimator for the OutputSlot at outputIndex.
long	getDatasetSize()
SampleOperator.Methods	getSampleMethod()
protected int	getSampleSize(OptimizationContext.OperatorContext operatorContext)	Retrieve the sample size for this instance w.r.t. the current iteration.
protected long	getSeed(OptimizationContext.OperatorContext operatorContext)	Retrieve the seed for this instance w.r.t. the current iteration.
DataSetType<Type>	getType()
protected boolean	isDataSetSizeKnown()	Find out whether this instance knows about the size of the incoming dataset.
static long	randomSeed()	Generate a random seed.
void	setDatasetSize(long datasetSize)
void	setSampleMethod(SampleOperator.Methods sampleMethod)
void	setSeedFunction(FunctionDescriptor.SerializableLongUnaryOperator seedFunction)

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

logger

protected final org.apache.logging.log4j.Logger logger

UNKNOWN_DATASET_SIZE

public static final long UNKNOWN_DATASET_SIZE

Special dataset size that represents "unknown".

See Also:

• Constant Field Values

sampleSizeFunction

protected FunctionDescriptor.SerializableIntUnaryOperator sampleSizeFunction

This function determines the sample size by the number of iterations.

seedFunction

protected FunctionDescriptor.SerializableLongUnaryOperator seedFunction

This function optionally determines the seed by the number of iterations.

datasetSize

protected Long datasetSize

Size of the dataset to be sampled or 0L if a dataset size is not known.

Constructor Details

SampleOperator

public SampleOperator(Integer sampleSize,
 DataSetType<Type> type)

Creates a new instance with any sampling method.

Parameters:

sampleSize - size of the sample

type - DataSetType of the sampled dataset

SampleOperator

public SampleOperator(FunctionDescriptor.SerializableIntUnaryOperator sampleSizeFunction,
 DataSetType<Type> type)

Creates a new instance with any sampling method.

Parameters:

sampleSizeFunction - user-specified size of the sample in dependence of the current iteration number

type - DataSetType of the sampled dataset

SampleOperator

public SampleOperator(Integer sampleSize,
 DataSetType<Type> type,
 SampleOperator.Methods sampleMethod,
 long seed)

Creates a new instance given the sample size and the seed.

SampleOperator

public SampleOperator(FunctionDescriptor.SerializableIntUnaryOperator sampleSizeFunction,
 DataSetType<Type> type,
 SampleOperator.Methods sampleMethod)

Creates a new instance given the sample size and the method.

SampleOperator

public SampleOperator(FunctionDescriptor.SerializableIntUnaryOperator sampleSizeFunction,
 DataSetType<Type> type,
 SampleOperator.Methods sampleMethod,
 long seed)

Creates a new instance given a user-defined sample size.

SampleOperator

public SampleOperator(FunctionDescriptor.SerializableIntUnaryOperator sampleSizeFunction,
 DataSetType<Type> type,
 SampleOperator.Methods sampleMethod,
 FunctionDescriptor.SerializableLongUnaryOperator seedFunction)

Creates a new instance given user-defined sample size and seed methods.

SampleOperator

public SampleOperator(SampleOperator<Type> that)

Copies an instance (exclusive of broadcasts).

Parameters:

that - that should be copied

Method Details

randomSeed

public static long randomSeed()

Generate a random seed.

getType

public DataSetType<Type> getType()

getDatasetSize

public long getDatasetSize()

setDatasetSize

public void setDatasetSize(long datasetSize)

isDataSetSizeKnown

protected boolean isDataSetSizeKnown()

Find out whether this instance knows about the size of the incoming dataset.

Returns:

whether it knows the dataset size

getSampleMethod

public SampleOperator.Methods getSampleMethod()

setSampleMethod

public void setSampleMethod(SampleOperator.Methods sampleMethod)

setSeedFunction

public void setSeedFunction(FunctionDescriptor.SerializableLongUnaryOperator seedFunction)

getSampleSize

protected int getSampleSize(OptimizationContext.OperatorContext operatorContext)

Retrieve the sample size for this instance w.r.t. the current iteration.

Parameters:

operatorContext - provides the current iteration number

Returns:

the sample size

getSeed

protected long getSeed(OptimizationContext.OperatorContext operatorContext)

Retrieve the seed for this instance w.r.t. the current iteration.

Parameters:

operatorContext - provides the current iteration number

Returns:

the seed

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