| Package | Description | 
|---|---|
| org.apache.hadoop.mapred.lib.aggregate | |
| org.apache.hadoop.mapreduce.lib.aggregate | 
| Modifier and Type | Interface and Description | 
|---|---|
interface  | 
ValueAggregator<E>
This interface defines the minimal protocol for value aggregators. 
 | 
| Modifier and Type | Class and Description | 
|---|---|
class  | 
DoubleValueSum
This class implements a value aggregator that sums up a sequence of double
 values. 
 | 
class  | 
LongValueMax
This class implements a value aggregator that maintain the maximum of 
 a sequence of long values. 
 | 
class  | 
LongValueMin
This class implements a value aggregator that maintain the minimum of 
 a sequence of long values. 
 | 
class  | 
LongValueSum
This class implements a value aggregator that sums up 
 a sequence of long values. 
 | 
class  | 
StringValueMax
This class implements a value aggregator that maintain the biggest of 
 a sequence of strings. 
 | 
class  | 
StringValueMin
This class implements a value aggregator that maintain the smallest of 
 a sequence of strings. 
 | 
class  | 
UniqValueCount
This class implements a value aggregator that dedupes a sequence of objects. 
 | 
class  | 
ValueHistogram
This class implements a value aggregator that computes the 
 histogram of a sequence of strings. 
 | 
| Modifier and Type | Method and Description | 
|---|---|
static ValueAggregator | 
ValueAggregatorBaseDescriptor.generateValueAggregator(String type,
                       long uniqCount)  | 
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