ITPEC FE Morning October 2023 Question 26

Normalization — the design process that splits tables so that each fact is stored only once.

Normalization decomposes a table step by step through normal forms (1NF, 2NF, 3NF) so that no non-key attribute depends on part of a key or on another non-key attribute. Each fact then lives in one place, which removes redundancy and the update anomalies it causes.

Answer (d)

Why not others:

• •(a) Entity-relationship — a modelling notation for entities and their relationships; it describes the data, it does not remove duplication
• •(b) Functional dependency — the relationship (X determines Y) that normalization analyses; it is the criterion, not the method
• •(c) Hierarchical — a kind of data model (a tree of parent and child records), not a technique for removing redundancy

Key rule: Functional dependencies tell you where redundancy is; normalization is the process that removes it by decomposing tables.

Databases · AI-written, may contain errors