Advanced Database Please solve it using Hadoop Assume that you have the following relations, each relation represents a dataset of text files stores on HDFS. 1. ratings ( UserID, MovieID, Rating ) //...

Advanced Database Please solve it using Hadoop

Assume that you have the following relations, each relation represents a dataset of
text files stores on HDFS.
1. ratings ( UserID, MovieID, Rating ) // where rating represent the rating between
(from 1 to 5) given by the user to the corresponding movieID
2. users ( UserID, Gender, Age)
3. movies ( MovieID, Title, Genres ) // where genres in the classification of the
movie such as comedy, children, action, ….
Suppose you have been given a task to find the average rating for each movie in
the form (movieID, Title, avg_rating). Computing the average rating must consider
the following:
4. only children and comedy movies
5. consider rating values that are above 2
6. consider ratings from users who’s age is above 25
What to submit:
• First briefly describe how to implement the above task in MapReduce jobs in an
efficient way
• specify how many jobs you need
• what the purpose of each MapReduce job (what it does)
• what the Map and Reduce functions do in each MapReduce Job. write that in
pseudo code similar to what we did in the lectures of relational algebra in
MapReduce