The release of N1QL Developer Preview 4 (DP4) from Couchbase represents a significant advancement in the query language's development, marking its completion in terms of syntax and language elements for building rich data applications. This version introduces new features such as subqueries and Data Manipulation Language (DML) constructs including INSERT, UPDATE, DELETE, and UPSERT, enhancing its capabilities for application development. DP4 also includes an array of new functions and operators like UNION, INTERSECT, and EXCEPT, alongside an upgraded command line interface supporting multi-line shell input and robust REST APIs for seamless interaction. Enthusiastic about community engagement, the developers encourage users to explore the new features through hands-on tutorials and provide feedback, while also addressing user queries related to performance comparisons and compatibility issues.