PrepAway - Latest Free Exam Questions & Answers

What does calling the next () method return?

In the reducer, the MapReduce API provides you with an iterator over Writable values. What does
calling the next () method return?

PrepAway - Latest Free Exam Questions & Answers

A.
It returns a reference to a different Writable object time.

B.
It returns a reference to a Writable object from an object pool.

C.
It returns a reference to the same Writable object each time, but populated with different data.

D.
It returns a reference to a Writable object. The API leaves unspecified whether this is a reused
object or a new object.

E.
It returns a reference to the same Writable object if the next value is the same as the previous
value, or a new Writable object otherwise.

Explanation:
Calling Iterator.next() will always return the SAME EXACT instance of IntWritable,
with the contents of that instance replaced with the next value.
Reference: manupulating iterator in mapreduce

2 Comments on “What does calling the next () method return?


Leave a Reply

Your email address will not be published. Required fields are marked *