Database Normalisation Questions Medium
In database normalization, both functional dependency and transitive dependency are concepts used to analyze and improve the structure of a database.
Functional dependency refers to the relationship between two sets of attributes within a relation (table) in a database. It occurs when the value of one set of attributes determines the value of another set of attributes. In other words, if we have a functional dependency A → B, it means that for every unique value of A, there is only one corresponding value of B. This helps in eliminating data redundancy and improving data integrity.
On the other hand, transitive dependency is a type of functional dependency that exists when there is a chain of functional dependencies within a relation. It occurs when the value of one attribute determines the value of another attribute indirectly through a third attribute. For example, if we have a transitive dependency A → B and B → C, it implies that A → C indirectly. Transitive dependencies can lead to data redundancy and anomalies, and they should be eliminated through normalization.
To summarize, the main difference between functional dependency and transitive dependency is that functional dependency represents a direct relationship between two sets of attributes, while transitive dependency represents an indirect relationship between attributes through a third attribute. Both are important considerations in database normalization to ensure data integrity and eliminate redundancy.