Domain Relational Calculus

Domain Relational Calculus (DRC) is a formal method used in database theory to specify queries. It describes what data to retrieve by focusing on the properties of the data's individual attributes (domains) rather than on the structure of the tables. In DRC, you write expressions that state conditions the desired data must meet, such as "find all employees whose salary is above $50,000." These expressions specify the criteria for selection, allowing a clear, logical way to define and retrieve specific data from a database without directly referencing its physical organization.