Question

Point out the correct statement.

(a) The reduce input must have the same types as the map output, although the reduce output types may be different again

(b) The map input key and value types (K1 and V1) are different from the map output types

(c) The partition function operates on the intermediate key

(d) All of the mentioned

The question was posed to me in final exam.

My question is based upon Mapreduce Types in division MapReduce Types and Formats of Hadoop

Answer 1

Right answer is (d) All of the mentioned

To elaborate: In practice, the partition is determined solely by the key (the value is ignored).