Question

2. Consider the following database of Empire Bank (a consortium of banks):
Employee (employee-name, street, city)
Works (employee-name, company-name, salary)
Company (company-name, city)
Manager (employee-name, manager-name)
Give an expression in the sql query and the relational algebraic expression(s) for the
following, providing the query optimization techniques involved:
(a) Find the names of all employees who work for Empire bank.
(b) Find the highest and lowest salary of employees in each city.
(c) Find the employee-name and salary of the employees who work for a company that has a
single bank in that city.

Answer 1

Answer:

" for" (and any subsequent of word): ignored because we limit queries to 32 words