com.pervasive.datarush.ports.record

Class PartialStaticDataDistribution

java.lang.Object

com.pervasive.datarush.ports.record.DataDistribution

com.pervasive.datarush.ports.record.PartialDataDistribution

com.pervasive.datarush.ports.record.PartialStaticDataDistribution

Direct Known Subclasses:

BalancedDistribution, KeyDrivenDataDistribution, UnspecifiedPartialDistribution

public abstract class PartialStaticDataDistribution
extends PartialDataDistribution

Base class for all distributions whose partitioning parameters are specified statically.

See Also:

DataDistribution

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PartialStaticDataDistribution() Default constructor.

Method Summary

Modifier and Type	Method and Description
protected abstract PartitioningFunction	getPartitioningFunction() Subclasses must override this method to provide the partitioning function to be used
protected abstract boolean	requiresRepartitionFrom(PartialDataDistribution source) Subclasses must override this method to declare whether a repartition is required given the source distribution.
protected boolean	supportsLocalRepartition() Subclasses may override to indicate that they support a local repartition

Methods inherited from class com.pervasive.datarush.ports.record.PartialDataDistribution

getGatherScheme

Methods inherited from class com.pervasive.datarush.ports.record.DataDistribution

getAliases, remap, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

PartialStaticDataDistribution

protected PartialStaticDataDistribution()

Default constructor.

Method Detail

supportsLocalRepartition

protected boolean supportsLocalRepartition()

Subclasses may override to indicate that they support a local repartition

Returns:

getPartitioningFunction

protected abstract PartitioningFunction getPartitioningFunction()

Subclasses must override this method to provide the partitioning function to be used

Returns:

a partition function

requiresRepartitionFrom

protected abstract boolean requiresRepartitionFrom(PartialDataDistribution source)

Subclasses must override this method to declare whether a repartition is required given the source distribution. Implementations may err on the side of caution by always returning true but this may have an impact on performance.

Parameters:

source - the source distribution

Returns:

true if a repartition is required, false if this data distribution matches what was specified.