Relaatiotietoa

Relaatiotietoa refers to the type of data represented within a relational database, a structured collection of facts organized in rows and columns. In this model, each table—called a relation—contains records that share the same attributes. The relational approach, formalized by Edgar F. Codd in 1970, emphasizes the use of set-theoretic principles to guarantee that data can be queried, joined, and manipulated efficiently through declarative commands such as SQL.

Critical concepts of relaatiotietoa include keys, which uniquely identify rows; foreign keys, which maintain referential integrity between tables; and various normal forms, which reduce redundancy and improve consistency. Relational algebra and relational calculus form the theoretical foundations for query operations, providing a mathematically rigorous framework for transforming and retrieving data.

Relaatiotietoa is distinguished from other data models by its strict reliance on a tabular structure and set-based operations. Although emerging models like NoSQL and graph databases offer flexibility for unstructured or highly connected data, relational databases remain the predominant choice for transactional applications requiring robust consistency, ACID compliance, and sophisticated query capabilities. They are widely implemented by systems such as Oracle, Microsoft SQL Server, PostgreSQL, MySQL, and many others, each supporting extensive features such as indexing, stored procedures, and transaction logs to manage relaatiotietoa at scale.