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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 organising data in a database to eliminate anomalies and reduce data redundancy. It involves structuring the database in such a way that dependencies are properly enforced and that data is stored in such a manner to minimize duplications.
Step 2
(a) Explain how this one-to-many relationship can be properly created by implementing the appropriate primary key/foreign key relationship in the design of the tables.
Answer
To create the one-to-many relationship, a foreign key needs to be added to the tblShows table that references the primary key of the tblArtists table. Specifically, the field ArtistID in tblShows will serve as a foreign key that links back to the ArtistID in tblArtists, indicating that each show is performed by one artist, while one artist can perform in many shows.
Step 3
(b) Identify the redundant field in tblArtists and motivate your answer.
Answer
The redundant field in tblArtists is likely the NumberOfShows. This is because the number of shows an artist performs can be derived from the tblShows table by counting the entries associated with each artist's ID, making this field unnecessary.
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 certain rules and relationships that have been defined within the database schema, thus preventing invalid or corrupt data from being stored.