Question

Which of the following class is provided by the Aggregate package?

(a) Map

(b) Reducer

(c) Reduce

(d) None of the mentioned

Answer 1

Right answer is (b) Reducer

To elaborate: Aggregate provides a special reducer class and a special combiner class, and a list of simple aggregators that perform aggregations such as “sum”, “max”, “min” and so on over a sequence of values.