public interface AggregateFunction<InputType,PartialAggregateType,FinalAggregateType>
extends java.io.Serializable
| Modifier and Type | Method and Description |
|---|---|
PartialAggregateType |
combine(PartialAggregateType partialAggregate1,
PartialAggregateType partialAggregate2)
Computes the combined aggregate from partial aggregates.
|
PartialAggregateType |
lift(InputType inputTuple)
Transforms a tuple to a partial aggregate.
|
FinalAggregateType |
lower(PartialAggregateType aggregate)
Transforms a partial aggregate to a final aggregate.
|
PartialAggregateType lift(InputType inputTuple)
inputTuple - input TuplePartialAggregateType combine(PartialAggregateType partialAggregate1, PartialAggregateType partialAggregate2)
partialAggregate1 - partialAggregate2 - FinalAggregateType lower(PartialAggregateType aggregate)
aggregate -