Description: Recursive data refers to data structured hierarchically, where an element can contain references to other elements of the same type. This structure allows for the representation of complex and nested relationships, such as those found in trees or graphs. In the context of databases, recursive data is particularly useful for modeling hierarchies, such as those found in organizations, product categories, or family structures. Recursion allows a record to reference itself, facilitating the representation of parent-child relationships. For example, in an employee table, a record may contain a field indicating the ID of the manager, which is itself a record in the same table. This referencing capability enables complex queries and efficient information retrieval, using techniques like recursion in SQL queries. The implementation of recursive data can vary depending on the database management system, but is generally achieved through recursive Common Table Expressions (CTEs), which allow for building results from an initial set of data and expanding it iteratively. In summary, recursive data is fundamental for the representation and manipulation of hierarchical structures in databases, offering flexibility and power in handling complex information.
