Q1) Data Management (20 marks)

Questions part 1 and part 2 refer to the Supplier-Part-Jobs database. The scheme for this database is as follows: CourseNana.COM

• suppliers (s_id, name, status, city) -- the information about suppliers
• parts (p_id, name, colour, weight, city) -- the information about parts
• job (j_id, name, city) -- the information about jobs
• supplier_inventory (s_id, p_id, quantity) -- the quantity of each part that suppliers currently hold
• requests (s_id, p_id, j_id, quantity) -- the amount of each part requested from a supplier for a job

Part 1 Relational Algebra (6 marks)

Please evaluate the following relational algebra expressions on the following presented subset of the Supplier-Parts-Jobs database. CourseNana.COM

Suppliers (S): CourseNana.COM

Parts (P): CourseNana.COM

Jobs (J): CourseNana.COM

Requests (R): CourseNana.COM

For a) and b) since you can't draw tables, please write your answer as comma separated values, including the column headers. e.g.
id, column2, column3
1, Trevor, Computing
2, James, Business
3, Sarah, Engineering CourseNana.COM

a) (2 marks) (?????????>200∧????????<=400  (?))⋈?$({\sigma }_{quantity>200\wedge quantity<=400}(R))\bowtie R$ CourseNana.COM

b) (2 marks) (????, ???(?×?))−(????, ???(?))$({\pi }_{s_{id},p_{id}}(S\times P))-({\pi }_{s_{id},p_{id}}(R))$ CourseNana.COM

c) (2 marks) Describe in English what the following RA computes: CourseNana.COM