The school stores all the information of the learners in a database with multiple tables - NSC Information Technology - Question 4 - 2023 - Paper 2

A primary key cannot have a null value. Every record must contain a value for the primary key field, ensuring that all records are identifiable.

(a) The design error in this table is that the Teacher field contains redundancy. If a teacher is replaced, all instances need to be updated.

(b) This design error can be resolved by creating a separate table for Teachers and linking it to tblLearners. This would involve establishing a foreign key relationship where each Teacher has a unique ID, thus ameliorating redundancy.

Verification ensures that data is correctly entered into the system, matching the source correctly. Validation, on the other hand, checks that the data is acceptable or falls within defined parameters. The key difference is that while validation ensures data meets certain criteria, it does not confirm the accuracy of the data against an original source.

The programming language most commonly used for extracting data from a database is SQL (Structured Query Language).

A typical scenario for using a server-based database would be in a school environment where multiple users need to access student records simultaneously from different locations. A server-based database allows concurrent access, ensuring that data remains consistent and updated.

An audit trail enhances data security by tracking changes made to the database. It records what actions were taken, when they were executed, and by whom, making it easier to identify unauthorized access or modifications.

Besides using an audit trail, implementing access controls can significantly enhance data security. This involves setting permissions to restrict user access based on their roles, using passwords, biometric verification, or other authentication means to safeguard sensitive data.