Method Aggregate

Aggregate(Object)

This method takes in an Object and contains the logic of applying the aggregation operation on the same node (locally) as is with Combiner. If you wish to combine the values using a aggregator before being sent for further processing in the Reducer, you can use the Aggregate() call.

Declaration

object Aggregate(object value)

Parameters

Type	Name	Description
System.Object	value	object

Returns

Type	Description
System.Object	Returns aggregated result.

Examples

Following example illustrate the implementation of Aggregate.

string function;
//setting current aggregator function

public IntAggregator(string function)
{
   this.function = function;
}

//Implementing interface function

public object Aggregate(object value)
{
   return calculate(value);
}
//Function to calculate values

private object calculate(object value)
{
   switch (function)
   {
       case "MIN":
           value = int.MinValue;
           return value;
       case "MAX":
           value = int.MaxValue;
           return value;
       default:
           return 0;
   }
}