org.kitesdk.data

Class PartitionStrategy

java.lang.Object

org.kitesdk.data.PartitionStrategy

@Immutable
public class PartitionStrategy
extends Object

The strategy used to determine how a dataset is partitioned.

When a Dataset is configured with a partition strategy, that data is considered partitioned. Any entities written to a partitioned dataset are evaluated with its PartitionStrategy to determine which partition to write to.

You should use the inner PartitionStrategy.Builder to create new instances.

See Also:

DatasetDescriptor, Dataset

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	PartitionStrategy.Builder A fluent builder to aid in the construction of PartitionStrategys.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object o)
int	getCardinality() Return the cardinality produced by the contained field partitioners.
int	hashCode()
String	toString()
String	toString(boolean pretty)

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

getCardinality

public int getCardinality()

Return the cardinality produced by the contained field partitioners.

This can be used to aid in calculating resource usage during certain operations. For example, when writing data to a partitioned dataset, you can use this method to estimate (or discover exactly, depending on the partition functions) how many leaf partitions exist.

Warning: This method is allowed to lie and should be treated only as a hint. Some partition functions are fixed (for example, hash modulo number of buckets), while others are open-ended (for example, discrete value) and depend on the input data.

Returns:

The estimated (or possibly concrete) number of leaf partitions.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

toString

public String toString(boolean pretty)

Parameters:

pretty - true to indent and format JSON

Returns:

this PartitionStrategy as its JSON representation