1. One of the methods usually used by Database Administrators to improve database performance is to use PL/SQL code Blocks, stored procedures, and functions instead of using usual actual SQL queries. a. Propose a scenario of a database problem related to IR 4.0 with at least THREE (3) tables that include master-detailed relationships. Write a complete PL/SQL program that enables the user to insert new data, update and delete existing data as well as retrieve data from the database instead of using actual queries. Use the concept of divide and conquer when developing your code and provide a separate procedure for each of the required operations. Test the PL/SQL program created by executing different scenarios that covers all the required operations. Make use of substitution variables to get the input from the user. Attach screen snapshot for the output [40 marks] b. Improve the performance of the database by writing a PL/SQL trigger to maintain the referential integrity constraints between the Master table and Detailed tables. For any record that is updated or deleted from the Master table, the related record(s) in the Detailed tables should be updated or deleted accordingly. Test the trigger by executing different update and delete queries on the Master table, that affect the Detailed table. Provide screen snapshots for the output [20 marks] 2. Database security is one of the critical tasks of in database administration. A database administrator is the person in charge of implementing the authentication as well as the authorization of the database. a. Propose a scenario of a database administrator who is responsible of a small company consisting of FIVE (5) employees. Using oracle SQL commands show how to authenticate all the users as well as grant them required authorizations to enter and use the database. Provide screenshots for your answer. b. Propose a scenario to differentiate between admin privileges as well as object privileges. In your scenario, you need to show how both admin and objects privileges that are assigned through an intermediary affect the grantee when the intermediary is dropped from the database. Use Oracle commands to implement the scenario and provide a justification for the output of your commands.