org.apache.beam.sdk.extensions.joinlibrary

Class Join

java.lang.Object

org.apache.beam.sdk.extensions.joinlibrary.Join

public class Join
extends java.lang.Object

Utility class with different versions of joins. All methods join two collections of key/value pairs (KV).

Constructor Summary

Constructors

Constructor and Description
Join()

Method Summary

Modifier and Type	Method and Description
static <K,V1,V2> PCollection<KV<K,KV<V1,V2>>>	fullOuterJoin(PCollection<KV<K,V1>> leftCollection, PCollection<KV<K,V2>> rightCollection, V1 leftNullValue, V2 rightNullValue) Full Outer Join of two collections of KV elements.
static <K,V1,V2> PCollection<KV<K,KV<V1,V2>>>	innerJoin(PCollection<KV<K,V1>> leftCollection, PCollection<KV<K,V2>> rightCollection) Inner join of two collections of KV elements.
static <K,V1,V2> PCollection<KV<K,KV<V1,V2>>>	leftOuterJoin(PCollection<KV<K,V1>> leftCollection, PCollection<KV<K,V2>> rightCollection, V2 nullValue) Left Outer Join of two collections of KV elements.
static <K,V1,V2> PCollection<KV<K,KV<V1,V2>>>	rightOuterJoin(PCollection<KV<K,V1>> leftCollection, PCollection<KV<K,V2>> rightCollection, V1 nullValue) Right Outer Join of two collections of KV elements.

Methods inherited from class java.lang.Object

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

Constructor Detail

Join

public Join()

Method Detail

innerJoin

public static <K,V1,V2> PCollection<KV<K,KV<V1,V2>>> innerJoin(PCollection<KV<K,V1>> leftCollection,
                                                               PCollection<KV<K,V2>> rightCollection)

Inner join of two collections of KV elements.

Type Parameters:

K - Type of the key for both collections

V1 - Type of the values for the left collection.

V2 - Type of the values for the right collection.

Parameters:

leftCollection - Left side collection to join.

rightCollection - Right side collection to join.

Returns:

A joined collection of KV where Key is the key and value is a KV where Key is of type V1 and Value is type V2.

leftOuterJoin

public static <K,V1,V2> PCollection<KV<K,KV<V1,V2>>> leftOuterJoin(PCollection<KV<K,V1>> leftCollection,
                                                                   PCollection<KV<K,V2>> rightCollection,
                                                                   V2 nullValue)

Left Outer Join of two collections of KV elements.

Type Parameters:

K - Type of the key for both collections

V1 - Type of the values for the left collection.

V2 - Type of the values for the right collection.

Parameters:

leftCollection - Left side collection to join.

rightCollection - Right side collection to join.

nullValue - Value to use as null value when right side do not match left side.

Returns:

A joined collection of KV where Key is the key and value is a KV where Key is of type V1 and Value is type V2. Values that should be null or empty is replaced with nullValue.

rightOuterJoin

public static <K,V1,V2> PCollection<KV<K,KV<V1,V2>>> rightOuterJoin(PCollection<KV<K,V1>> leftCollection,
                                                                    PCollection<KV<K,V2>> rightCollection,
                                                                    V1 nullValue)

Right Outer Join of two collections of KV elements.

Type Parameters:

K - Type of the key for both collections

V1 - Type of the values for the left collection.

V2 - Type of the values for the right collection.

Parameters:

leftCollection - Left side collection to join.

rightCollection - Right side collection to join.

nullValue - Value to use as null value when left side do not match right side.

Returns:

A joined collection of KV where Key is the key and value is a KV where Key is of type V1 and Value is type V2. Values that should be null or empty is replaced with nullValue.

fullOuterJoin

public static <K,V1,V2> PCollection<KV<K,KV<V1,V2>>> fullOuterJoin(PCollection<KV<K,V1>> leftCollection,
                                                                   PCollection<KV<K,V2>> rightCollection,
                                                                   V1 leftNullValue,
                                                                   V2 rightNullValue)

Full Outer Join of two collections of KV elements.

Type Parameters:

K - Type of the key for both collections

V1 - Type of the values for the left collection.

V2 - Type of the values for the right collection.

Parameters:

leftCollection - Left side collection to join.

rightCollection - Right side collection to join.

leftNullValue - Value to use as null value when left side do not match right side.

rightNullValue - Value to use as null value when right side do not match right side.

Returns:

A joined collection of KV where Key is the key and value is a KV where Key is of type V1 and Value is type V2. Values that should be null or empty is replaced with leftNullValue/rightNullValue.