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FullOuterJoinFn (Apache Crunch 0.9.0 API)

Class FullOuterJoinFn<K,U,V>

  extended by org.apache.crunch.DoFn<Pair<Pair<K,Integer>,Iterable<Pair<U,V>>>,Pair<K,Pair<U,V>>>
      extended by org.apache.crunch.lib.join.JoinFn<K,U,V>
          extended by org.apache.crunch.lib.join.FullOuterJoinFn<K,U,V>
Type Parameters:
K - Type of the keys.
U - Type of the first PTable's values
V - Type of the second PTable's values
All Implemented Interfaces:

public class FullOuterJoinFn<K,U,V>
extends JoinFn<K,U,V>

Used to perform the last step of an full outer join.

See Also:
Serialized Form

Field Summary
Fields inherited from class org.apache.crunch.lib.join.JoinFn
keyType, leftValueType
Constructor Summary
FullOuterJoinFn(PType<K> keyType, PType<U> leftValueType)
Method Summary
 void cleanup(Emitter<Pair<K,Pair<U,V>>> emitter)
          Called during the cleanup of the MapReduce job this DoFn is associated with.
 String getJoinType()
 void initialize()
          Initialize this DoFn.
 void join(K key, int id, Iterable<Pair<U,V>> pairs, Emitter<Pair<K,Pair<U,V>>> emitter)
          Performs the actual joining.
Methods inherited from class org.apache.crunch.lib.join.JoinFn
Methods inherited from class org.apache.crunch.DoFn
configure, disableDeepCopy, getConfiguration, getContext, getCounter, getCounter, getStatus, getTaskAttemptID, increment, increment, increment, increment, progress, scaleFactor, setConfiguration, setContext, setStatus
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail


public FullOuterJoinFn(PType<K> keyType,
                       PType<U> leftValueType)
Method Detail


public void initialize()
Initialize this DoFn. This initialization will happen before the actual DoFn.process(Object, Emitter) is triggered. Subclasses may override this method to do appropriate initialization.

Called during the setup of the job instance this DoFn is associated with.

initialize in class JoinFn<K,U,V>


public void join(K key,
                 int id,
                 Iterable<Pair<U,V>> pairs,
                 Emitter<Pair<K,Pair<U,V>>> emitter)
Performs the actual joining.

Specified by:
join in class JoinFn<K,U,V>
key - The key for this grouping of values.
id - The side that this group of values is from (0 -> left, 1 -> right).
pairs - The group of values associated with this key and id pair.
emitter - The emitter to send the output to.


public void cleanup(Emitter<Pair<K,Pair<U,V>>> emitter)
Called during the cleanup of the MapReduce job this DoFn is associated with. Subclasses may override this method to do appropriate cleanup.

cleanup in class DoFn<Pair<Pair<K,Integer>,Iterable<Pair<U,V>>>,Pair<K,Pair<U,V>>>
emitter - The emitter that was used for output


public String getJoinType()

Specified by:
getJoinType in class JoinFn<K,U,V>
The name of this join type (e.g. innerJoin, leftOuterJoin).

Copyright © 2014 The Apache Software Foundation. All Rights Reserved.