Q$2.$ A database storing information about employees and their salaries contains the employee and

remuneration relations below. Answer the questions that follow.

EMPLOYEE

REMUNERATION

$($i$)$ A programmer, Mary, needs to access some but not all of the data in the employee relation

on a regular basis. Describe how she can be given access to all employee's id numbers, first

names and surnames but not their date of birth and provide the code in SQL$.$

$[6$ Marks$]$

$($ii$)$ The owner of the company, Michelle, has decided to give a salary of no less than $20,000$

$($euro$)$ to everyone who does not receive a bonus and is not eligible for outside earnings. How

should this constraint be applied to the remuneration relation?

$[7$ Marks$]$

$($iii$)$ In the below schedule, two transactions, Course Registration and Course Transfer, are

executing concurrently. Describe in detail what takes place in the case that Course Transfer

fails and is rolled back on its final write operation.

$($iv$)$ In the below schedule, two transactions, Course Registration and Course Transfer, are again

executing concurrently. Describe in detail what takes place in terms of data consistency.

$[6$ Marks$]$