Class Merge

  extended by cascading.pipe.Pipe
      extended by cascading.pipe.Splice
          extended by 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, 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, getStepConfigDef, getTrace, hasConfigDef, hasStepConfigDef, named, names, pipes, print, resolveIncomingOperationArgumentFields
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail


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

pipes -


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

name -
pipes -

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