Cardinality defines the number of relationships between two or more entities in databases. It determines how many records from one table relate to records in another. This concept plays a crucial role in relational database design and data analysis.
Types of Cardinality
Different types of cardinality exist. Minimum cardinality sets the lowest number of entities required to form a relationship. In contrast, maximum cardinality defines the highest number of entities involved in a specific relationship. Common relationships include one-to-one (1:1), one-to-many (1:M), and many-to-many (M:N).
Applications and Benefits of Cardinality
Database modeling frequently relies on cardinality. It ensures efficient data storage, optimizes query performance, and prevents inconsistencies. Data analysis also benefits from cardinality, as it helps uncover relationships between variables. Additionally, ER diagrams (Entity-Relationship diagrams) use cardinality to visualize entity connections.
Advantages of Cardinality
Cardinality improves database performance, maintains data integrity, and clarifies relationships between tables. Properly defining cardinality keeps data consistent and reduces redundancy.