Package org.apache.hadoop.hbase.mapreduce

Class TableReducer<KEYIN,VALUEIN,KEYOUT>

java.lang.Object
org.apache.hadoop.mapreduce.Reducer<KEYIN,VALUEIN,KEYOUT,Mutation>
org.apache.hadoop.hbase.mapreduce.TableReducer<KEYIN,VALUEIN,KEYOUT>
Type Parameters:
KEYIN - The type of the input key.
VALUEIN - The type of the input value.
KEYOUT - The type of the output key.
Direct Known Subclasses:
IdentityTableReducer
@Public public abstract class TableReducer<KEYIN,VALUEIN,KEYOUT> extends org.apache.hadoop.mapreduce.Reducer<KEYIN,VALUEIN,KEYOUT,Mutation>
Extends the basic Reducer class to add the required key and value input/output classes. While the input key and value as well as the output key can be anything handed in from the previous map phase the output value must be either a Put or a Delete instance when using the TableOutputFormat class.

This class is extended by IdentityTableReducer but can also be subclassed to implement similar features or any custom code needed. It has the advantage to enforce the output value to a specific basic type.

See Also:
  • Reducer

  • Nested Class Summary

    Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.Reducer

    org.apache.hadoop.mapreduce.Reducer.Context

  • Constructor Summary

    Constructors
    Constructor
    Description
    TableReducer()
     

  • Method Summary

    Methods inherited from class org.apache.hadoop.mapreduce.Reducer

    cleanup, reduce, run, setup

    Methods inherited from class java.lang.Object

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