(h) Programmers have to specify two functions when implementing a map/reduce computation model, however usually they also specifiy partition and combine. i. Explain what is meant by a combine and its purpose. (3mark2 ii. Another phase of the MapReduce algorithm is called shuffle/sort. For this phase explain 1. Who is responsible. (framework/programmer/customizable) 2. What it does. 3. What the input is like. 4. What the output is like. (4mark2 (i) Using map/reduce solve the following: The input is a list of housing data where each input record contains information about a single house: (address, city, county, eircode, value). The output should be the average house value in each county. Explain how the input is mapped into (key, value) pairs by the map stage, i.e., specify what is the key and what is the associated value in each pair, and, if needed, how the key(s) and value(s) are computed. Then explain how the (key, value) pairs produced by the map stage are processed by the reduce stage to get the final answer(s). If the job cannot be done in a single map-reduce pass, describe how it would be structured into two or more map-reduce jobs with the output of the first job becoming input to the next one(s). Just describe your solution algorithm