Question

Part 2. Algorithms for Big Data Programming (48 points total for this part) [Question 1, 12 points total, including 1.1 - 1.3] Suppose our input data to a map-reduce operation consists of integer values (that is, the values are integers, note the keys are not important). The map function takes an integer i and produces the list of pairs (1) such that p is a prime divisor of į. For example, map(12) = [(2,12),(3,12)]. The reduce function is addition. That is, reduce(p.[i,i2...... d) is (p,ii+is+...+ix). For this input set, 15, 21, 24, 30, 49 manually run this map-reduce operation and answer the following two questions: 1.1 (5 points) write the output from the map operation, i.e., for each input integer, what are the pairs generated? your answer: 1.2 (4 points) write the output from the mid-stage, i.e. the stage after the map operation, but before the reduce operation your answer: 1.3 (3 points) in the list below, identify the ONLY one pair that is created by the final output. a. (5, 49) b. (786) States) O Focus

Answer 1

Answer:

Part 1.1

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15 - [(3,15),(5,15)]

21 - [(3,21),(7,21)]

24 - [(2,24),(3,24)]

30 - [(2,30),(3,30),(5,30)]

49 - [(7,49)]

Part 1.2

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15 - reduce(15,[3,5))

21 - reduce(21,[3,7])

24 - reduce(24,[2,3])

30 - reduce(30,[2,3,5])

49 - reduce(49,[7])

For reference, After reduction final result:

15- (15,8)

21 - (21,10)

24 - (24,5)

30 - (30,10)

49 - (49,7)