Unit 3: Databases & Data Management

Answer: B — Option C is correct because a relational database model with separate tables for employees and job titles allows for efficient storage and retrieval of data, while minimizing data redundancy. This approach supports the requirement that each employee's name and address are stored only once, while allowing for multiple job titles to be associated with each employee. Option A is incorrect because storing all employee information in a single table with multiple columns for job titles would result in data redundancy and make it difficult to manage changes to job titles. Option B is incorrect because a hierarchical database model is not well-suited for storing complex relationships between data entities. Option D is incorrect because storing all job title information in a single table with multiple columns for employee names and addresses would result in data redundancy and make it difficult to manage changes to employee information.

Answer: A — The correct answer is A because a one-to-many relationship between the department table and the employee table accurately reflects the scenario, where one department can have multiple employees, but each employee is only assigned to one department. Option B is incorrect because a many-to-many relationship would imply that an employee can be assigned to multiple departments, which is not the case. Option C is incorrect because a one-to-one relationship would imply that each department has only one employee, which is also not the case. Option D is incorrect because a self-referential relationship within the employee table would not accurately model the relationship between departments and employees.

Answer: D — Option C is the correct answer because it uses normalization to minimize data redundancy and improve data integrity. By creating separate tables for employees and departments, and using a foreign key to link the two tables, the database can ensure that each piece of data is stored in one place and one place only. This makes it easier to maintain and update the data, and reduces the risk of errors and inconsistencies. Option A is incorrect because it would result in data redundancy, with each employee's department information being repeated in the table. Option B is incorrect because it would also result in data redundancy, and would make it difficult to update the department information. Option D is incorrect because it would result in a large number of tables, each with redundant data, and would make it difficult to maintain and update the data.

Answer: B — Option C is the correct answer because it establishes a one-to-many relationship between the department and employee tables, allowing for efficient querying and data management. Option A is incorrect because it would result in data redundancy and make it difficult to maintain data consistency. Option B is incorrect because it would not allow for easy querying of department information. Option D is incorrect because it would establish a many-to-one relationship in the wrong direction, making it difficult to manage employee assignments to departments.

Answer: B — The correct answer is A because the primary purpose of a database is to store and manage large amounts of organized data. In this scenario, the company needs to store information about its employees, departments, and project assignments, making a database the ideal solution. Options B, C, and D are incorrect because while databases can be used for data analysis, visualization, and integration with other systems, these are not their primary purpose.