Oxford, Cambridge and RSA (OCR) GCSE Computer Science Paper 2 Practice

Primary keys are crucial in database design because they ensure each record in a table is unique. This uniqueness is essential for accurately identifying and accessing individual records without confusion. When each record has a distinct primary key, it prevents duplication of data and allows for reliable data operations, such as insertions, updates, and deletions.

Moreover, having a unique identifier for each record makes it easier to establish relationships with other tables in the database, as the primary key from one table can serve as a foreign key in another. This connection is fundamental to maintaining referential integrity within the database, although establishing these links is not the primary function of the primary key itself.

While primary keys can contribute to performance enhancements in data retrieval and facilitate simpler query operations, these advantages stem from their role in maintaining unique identifiers rather than being their primary purpose. Ensuring uniqueness is the foundational aspect of primary keys that provides a coherent structure for organizing data and supporting various database functionalities.