ahmedosama93 / big-data

Tasks

Question 1:

Consider the following data items where each item represents a record on a table; each record is have 3 values (Table name, PK, AttributeValue). The database schema of the tables can be described as follow: T1(A1,A2) T2(A3,A1) The data items are as follow: (T1, 1, x) (T1, 2, x) (T1, 3, x) (T1, 4, y) (T1, 5, y) (T1, 6, y) (T1, 7, z) (T1, 8, z) (T2, A, 1) (T2, B, 2) (T2, C, 3)

1- Write a map/reduce program to do an inner join between T1 and T2 where A1 in T1 is a foreign key in T2. The query results should be: (A, 1,X) (B, 2,X) (C, 3,X)

2- Write a map/reduce program to do a full outer join between T1 and T2 where A1 in T1 is a foreign key in T2. The query results should be: (A, 1,X) (B, 2,X) (C, 3,X) (null, 4, y) (null, 5, y)(null, 6, y) (null, 7, z) (null, 8, z)

3- Write a map/reduce program to find out the difference between two attributes. For example : A1[T1] – A1[T2] , The result would [4,5,6,7,8]

Question 2: Consider the following data items where each item represents a friendship relationship between persons: (P1,P2) (P1,P3) (P3,P4) (P2,P4) (P2,P5)

Write a map/reduce program to find the friends of friends for a given person For example: find the friends of P1 friends P1 friends would be: P2, P3 Friends of P2 and P3 are (P4, P5)