org.apache.beam.sdk.transforms

Class ApproximateUnique.PerKey<K,V>

java.lang.Object

org.apache.beam.sdk.transforms.PTransform<PCollection<KV<K,V>>,PCollection<KV<K,java.lang.Long>>>

org.apache.beam.sdk.transforms.ApproximateUnique.PerKey<K,V>

Type Parameters:

K - the type of the keys in the input and output PCollections

V - the type of the values in the input PCollection

All Implemented Interfaces:

java.io.Serializable, HasDisplayData

Enclosing class:

ApproximateUnique

public static final class ApproximateUnique.PerKey<K,V>
extends PTransform<PCollection<KV<K,V>>,PCollection<KV<K,java.lang.Long>>>

PTransform for estimating the number of distinct values associated with each key in a PCollection of KVs.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.beam.sdk.transforms.PTransform

name

Constructor Summary

Constructors

Constructor and Description
PerKey(double estimationError)
PerKey(int sampleSize)

Method Summary

Modifier and Type	Method and Description
PCollection<KV<K,java.lang.Long>>	expand(PCollection<KV<K,V>> input) Override this method to specify how this PTransform should be expanded on the given InputT.
void	populateDisplayData(DisplayData.Builder builder) Register display data for the given transform or component.

Methods inherited from class org.apache.beam.sdk.transforms.PTransform

compose, compose, getAdditionalInputs, getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, toString, validate

Methods inherited from class java.lang.Object

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

Constructor Detail

PerKey

public PerKey(int sampleSize)

See Also:

ApproximateUnique.perKey(int)

PerKey

public PerKey(double estimationError)

See Also:

ApproximateUnique.perKey(double)

Method Detail

expand

public PCollection<KV<K,java.lang.Long>> expand(PCollection<KV<K,V>> input)

Description copied from class: PTransform

Override this method to specify how this PTransform should be expanded on the given InputT.

NOTE: This method should not be called directly. Instead apply the PTransform should be applied to the InputT using the apply method.

Composite transforms, which are defined in terms of other transforms, should return the output of one of the composed transforms. Non-composite transforms, which do not apply any transforms internally, should return a new unbound output and register evaluators (via backend-specific registration methods).

Specified by:

expand in class PTransform<PCollection<KV<K,V>>,PCollection<KV<K,java.lang.Long>>>

populateDisplayData

public void populateDisplayData(DisplayData.Builder builder)

Description copied from class: PTransform

Register display data for the given transform or component.

populateDisplayData(DisplayData.Builder) is invoked by Pipeline runners to collect display data via DisplayData.from(HasDisplayData). Implementations may call super.populateDisplayData(builder) in order to register display data in the current namespace, but should otherwise use subcomponent.populateDisplayData(builder) to use the namespace of the subcomponent.

By default, does not register any display data. Implementors may override this method to provide their own display data.

Specified by:

populateDisplayData in interface HasDisplayData

Overrides:

populateDisplayData in class PTransform<PCollection<KV<K,V>>,PCollection<KV<K,java.lang.Long>>>

Parameters:

builder - The builder to populate with display data.

See Also:

HasDisplayData