Question#1: - Consider the relational database below, where the primary keys are underlined. Below is an instance of the database.

- Give an expression in relational algebra for each of the following requests:

(a) Find the person-name and company-name of persons who are working in a city called Glasgow. Output the result to a relation called result.

(b) Find the persons who are working for companies which are located at different cities from the cities in which the persons are living.

(c) Find the lowest salary.

(d) Modify the database so that Jones now lives in Newtown.

(e) Give all managers in this database a 10 percent salary raise, unless the raised salary would be greater than $100,000. In such cases, give only a 3 percent raise.

employee (person-name, street, city) works (person-name, company-name, salary) company (company-name, city) manages (person-name, manager-name) Below is an instance of the database COMPANY companv-na me CI ABC XYZ EMPLOYEE rson-name street Alice Jones Bob Main street El Camino ave Commonwealth ave Arcadia cit Glasgow Hampshire Glasgow Newtowin MANAGES WORKS person-name company-name salary Bob Jones Alice rson-name manager-name Alice 99000 10000 120000 Bob XYZ ABC