Declarative query languages have shifted the focus from database engines to what needs to be retrieved, allowing for more efficient and flexible data access. N1QL, a declarative query language used in Couchbase Server 7.0, enables users to instruct the query language on how to retrieve specific data without specifying the underlying programming logic. User-defined functions (UDFs) provide an additional layer of control over queries by allowing users to define custom business logic and extend the capabilities of N1QL. UDFs can be created using inline or JavaScript, with each offering distinct benefits and use cases. The Couchbase Server 7.0 release introduces Scopes and Collections, which enable users to organize their JSON documents and further enhance data management capabilities. By leveraging UDFs, developers can write more efficient and effective queries, taking advantage of the strengths of both relational and document databases.