The Couchbase Server 4.0 GA introduced N1QL, enabling developers to develop with agility and operate at scale. The upcoming release of 4.1 includes a valuable stability fix and the developer preview release of Covering Indexes, a key feature that provides significant query performance improvements in many cases. A covering index allows an application to recognize noticeable query performance improvement by leveraging it appropriately. By using a covering index, applications can avoid unnecessary steps in the query execution flow, resulting in improved performance. The Couchbase Server 4.1 release introduces support for covering indexes through the EXPLAIN statement, allowing developers to see how the query execution plan is optimized with a covering index. This feature is particularly useful for queries that return all fields from an index, such as selecting multiple attributes or using expressions and aggregates. Developers are encouraged to try this feature in the 4.1 developer preview and provide valuable feedback.