The Couchbase 6.5 release is a significant one, bringing Enterprise Database functionalities to the N1QL Query service. This update expands N1QL with additional functions to support Enterprise Application requirements, aiming to improve developer productivity. Key features include full-text search capabilities, window and analytical functions, common table expressions, user-defined functions, subquery joins, and an Index Advisor tool. These enhancements enable more complex business questions, intuitive query constructs, and optimized query performance. The release includes Developer Preview features, such as Index Advisor, which allows users to create the most optimum indexes for their queries.