Description: A natural key is a fundamental concept in the design of relational databases, referring to a set of attributes used to uniquely identify an entity in the real world. Unlike surrogate keys, which are generated specifically for the system and have no meaning outside of it, natural keys are based on data that already exists in the real environment. For example, a national identification number, a vehicle registration number, or an email address can serve as natural keys. These keys are valuable because they reflect information that is relevant and understandable to users, facilitating data integration and interoperability between systems. Additionally, the use of natural keys can improve data quality, as they are based on attributes that are inherently unique and stable over time. However, they also present challenges, such as the possibility of changes in attributes that can affect the integrity of the database. In summary, natural keys are essential for the precise identification of entities in databases, providing both advantages and considerations to keep in mind during implementation.
