public interface Aggregator<V,R,A extends Aggregator<V,R,A>>
extends java.io.Serializable
Behavior of a user-defined Derby aggregator. Aggregates values of type V and returns a result of type R. In addition to the methods in the interface, implementing classes must have a 0-arg public constructor.
Modifier and Type | Method and Description |
---|---|
void |
accumulate(V value)
Accumulate the next scalar value
|
void |
init()
Initialize the Aggregator
|
void |
merge(A otherAggregator)
For merging another partial result into this Aggregator.
|
R |
terminate()
Return the result scalar value
|
void init()
void accumulate(V value)
void merge(A otherAggregator)
R terminate()
Apache Derby 10.10 API Documentation - Copyright © 2004,2013 The Apache Software Foundation. All Rights Reserved.