Final Answer:
ENUM is the best choice for storing student grades as letter values due to its predefined set, efficiency, and data integrity, ensuring accurate representation and streamlined database operations.
Therefore the best answer is d) ENUM
Step-by-step explanation:
In database schema design for storing student grades as letter grades (A, B, C, D, or F), the most suitable column type would be ENUM. ENUM stands for enumeration, allowing a predefined set of possible values, in this case, the letter grades. While VARCHAR could also be used, it allows a wider range of characters and doesn't inherently restrict input to specific values like ENUM does. INT and CHAR are not optimal choices for storing letter grades, as INT is typically used for numerical values, while CHAR would require more storage space than necessary for single-character grades.
ENUM provides a clear and concise way to define and restrict the possible values to the specified letter grades (A, B, C, D, or F) without compromising on storage or query efficiency. It's efficient in terms of storage as it uses minimal space to represent each grade. For instance, a column of type ENUM for grades could use only one byte per entry, compared to VARCHAR or CHAR, which might use more space. Additionally, ENUM ensures data integrity by limiting input to the predefined set of values, preventing the insertion of invalid grades.
Using ENUM simplifies database operations, enhances data consistency, and streamlines queries involving grades. It's an ideal choice for maintaining a structured and controlled set of options, ensuring the database accurately represents student grades without unnecessary overhead or ambiguity.
Therefore the best answer is d) ENUM