cascading.pipe
Class Merge

java.lang.Object
  cascading.pipe.Pipe
      cascading.pipe.Splice
          cascading.pipe.Merge

All Implemented Interfaces:

FlowElement, Serializable

public class Merge
extends Splice

The Merge Pipe allows for multiple branches, with the same fields to be spliced back into a single stream.

The behavior is similar to the GroupBy merging features, but Merge does not perform any grouping or sorting on keys. Thus, when using a MapReduce platform, no Reducer is required.

Merge is non-blocking and performs no processing. Any number of branches and merges may be performed in a Flow without triggering any additional MapReduce jobs on the Hadoop platform.

Unlike HashJoin, no preference need be made for left-hand or right-hand sided-ness of streams in relation to their sizes.

See Also:

GroupBy, Serialized Form

Field Summary

Fields inherited from class cascading.pipe.Splice

declaredFields, keyFieldsMap, resultGroupFields, sortFieldsMap

Fields inherited from class cascading.pipe.Pipe

configDef, name, parent, previous, stepConfigDef

Constructor Summary

Merge(Pipe... pipes)
Constructor Merge creates a new Merge instance.

Merge(String name, Pipe... pipes)
Constructor Merge creates a new Merge instance.

Method Summary

Methods inherited from class cascading.pipe.Splice

equals, getDeclaredFields, getJoiner, getKeySelectors, getName, getNumSelfJoins, getPipePos, getPrevious, getSortingSelectors, hashCode, isCoGroup, isEquivalentTo, isGroupBy, isJoin, isMerge, isSorted, isSortReversed, outgoingScopeFor, printInternal, resolveIncomingOperationPassThroughFields, toString

Methods inherited from class cascading.pipe.Pipe

getConfigDef, getHeads, getParent, getStepConfigDef, getTrace, hasConfigDef, hasStepConfigDef, id, named, names, pipes, print, resolveIncomingOperationArgumentFields, setParent

Methods inherited from class java.lang.Object

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

Constructor Detail

Merge

@ConstructorProperties(value="pipes")
public Merge(Pipe... pipes)

Constructor Merge creates a new Merge instance.

Parameters:

pipes -

Merge

@ConstructorProperties(value={"name","pipes"})
public Merge(String name,
                                        Pipe... pipes)

Constructor Merge creates a new Merge instance.

Parameters:

name -

pipes -