The introduction of user-defined functions (UDFs) in Couchbase Server 7.0's Analytics Service allows users to create reusable and parameterizable SQL++ queries, enhancing modularity and control over data interactions. UDFs consist of a function signature, which includes the function name and parameters, and a function body, which can be an expression or subquery. These functions can be created within specific dataverses or scopes and offer improved code reuse and flexibility. For example, a UDF can be used to query and rank airlines based on route counts within a given country, streamlining complex queries by performing operations such as joins and aggregations on Collections. Once a UDF is no longer needed, it can be easily dropped. The new functionality is aimed at optimizing query processes in Couchbase Analytics, and users are encouraged to explore this feature and provide feedback.