Class RightOuterJoinFn<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.RightOuterJoinFn<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 RightOuterJoinFn<K,U,V>
extends JoinFn<K,U,V>

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

See Also:
Serialized Form

Constructor Summary
RightOuterJoinFn(PType<K> keyType, PType<U> leftValueType)
Method Summary
 String getJoinType()
 void initialize()
          Called during the setup of the MapReduce job this DoFn is associated with.
 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
cleanup, configure, scaleFactor, setConfigurationForTest, setContext
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail


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


public void initialize()
Called during the setup of the MapReduce job this DoFn is associated with. Subclasses may override this method to do appropriate initialization.

initialize in class DoFn<Pair<Pair<K,Integer>,Iterable<Pair<U,V>>>,Pair<K,Pair<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 String getJoinType()

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

Copyright © 2012 The Apache Software Foundation. All Rights Reserved.