Showing posts with the label Temporal Databases

Database Management System Que & Ans

Que - Explain functional dependency and its types with examples in detail. Ans -   Functional dependency is a crucial concept in the field of relational databases. It describes the relationship between attributes (or columns) in a relation (or table). In simpler terms, it tells us how one attribute's value determines another attribute's value within a table. Let's dive deeper into the definition and types of functional dependencies with examples: Definition: A functional dependency � → � X → Y in a relation holds if and only if, for every valid instance of � X , there is exactly one corresponding instance of � Y . This means that if two tuples (rows) in a relation agree on a set of values for � X , they must also agree on the corresponding values for � Y . Types of Functional Dependencies: Full Functional Dependency: A full functional dependency occurs when removing any attribute from the determinant � X results in a loss of the functional dependency. In other words,