Couchbase Server 6.5 introduces new features to its NoSQL database, notably adding window functions to the N1QL query language, which enhance the database's ability to handle complex business queries efficiently. These window functions are executed in a distributed, partition-parallel manner in the Couchbase Analytics service, leveraging the MPP query engine that isolates workload from operational nodes and employs a parallel processing approach across multiple nodes. The execution plan of window functions involves data repartitioning, sorting, and computation, allowing for scalable and efficient data analysis. Additionally, N1QL for Analytics offers flexibility by allowing window functions in various clauses, unlike traditional SQL, and these functions can be directly applied to JSON data, simplifying the data processing workflow. The server's architecture supports memory management and resource-based load control to ensure efficient query execution, making it a powerful tool for real-time data analysis and reporting.