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4.1.1 Explain the concept of database normalisation in the design of a database - NSC Information Technology - Question 4 - 2024 - Paper 2
Question 4
4.1.1 Explain the concept of database normalisation in the design of a database. 4.1.2 A relationship needs to be created between the tblArtists and tblShows tables... show full transcript
Worked Solution & Example Answer:4.1.1 Explain the concept of database normalisation in the design of a database - NSC Information Technology - Question 4 - 2024 - Paper 2
Step 1
Explain the concept of database normalisation in the design of a database.
Answer
Database normalisation is the process of organizing data in a database to reduce redundancy and improve data integrity. It involves structuring a database in a way that ensures relationships between data are logical, which helps in eliminating anomalies that can arise during data operations like insertion, updating, or deletion.
Step 2
(a) This relationship should allow each show to be performed by one artist, and each artist to be able to perform in many shows. Explain how this one-to-many relationship can be properly created by implementing the appropriate primary key/foreign key relationship in the design.
Answer
To create this one-to-many relationship, the primary key ArtistID from the tblArtists table should become a foreign key in the tblShows table. This way, each show can reference an artist through the ArtistID, allowing multiple shows to be associated with the same artist while ensuring that each show is linked to one distinct artist.
Step 3
(b) Identify the redundant field in tblArtists and motivate your answer.
Answer
The redundant field in tblArtists is likely NumberOfShows. This field can be derived by counting the number of entries related to each artist in the tblShows table. Including it within tblArtists violates the principle of normalization by introducing redundancy, as the same data can be obtained through a join operation.
Step 4
Explain what is meant by the term logical integrity.
Answer
Logical integrity refers to the accuracy and consistency of the data within a database. It ensures that the data conforms to the rules defined, such as data types and formats, and that relationships among data elements are maintained correctly, preventing situations where the data could exist in an invalid or unsynchronized state.