Package org.apache.hadoop.mapred.lib.aggregate

Class UniqValueCount

java.lang.Object

org.apache.hadoop.mapreduce.lib.aggregate.UniqValueCount

org.apache.hadoop.mapred.lib.aggregate.UniqValueCount

All Implemented Interfaces:

ValueAggregator<Object>, ValueAggregator<Object>

@Public
@Stable
public class UniqValueCount
extends UniqValueCount
implements ValueAggregator<Object>

This class implements a value aggregator that dedupes a sequence of objects.

Field Summary

Fields inherited from class org.apache.hadoop.mapreduce.lib.aggregate.UniqValueCount

MAX_NUM_UNIQUE_VALUES

Constructor Summary

Constructors

Constructor	Description
UniqValueCount()	the default constructor
UniqValueCount(long maxNum)	constructor

Method Summary

Methods inherited from class org.apache.hadoop.mapreduce.lib.aggregate.UniqValueCount

addNextValue, getCombinerOutput, getReport, getUniqueItems, reset, setMaxItems

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.mapreduce.lib.aggregate.ValueAggregator

addNextValue, getCombinerOutput, getReport, reset

Constructor Details

UniqValueCount

public UniqValueCount()

the default constructor

UniqValueCount

public UniqValueCount(long maxNum)

constructor

Parameters:

maxNum - the limit in the number of unique values to keep.