Amazon DocumentDB (with MongoDB compatibility) adds the $out aggregation stage and increases the maximum number of connections and cursors
Amazon DocumentDB (with MongoDB compatibility) is a fast, scalable, highly available, and fully managed document database service that supports MongoDB workloads. As a document database, Amazon DocumentDB makes it easy to store, query, and index JSON data.
Amazon DocumentDB continues to increase compatibility with MongoDB and today added support $out aggregation stage. The supported MongoDB APIs and aggregation pipeline capabilities for Amazon DocumentDB can be found here. With this launch, Amazon DocumentDB also increased the maximum number of connections and cursor per instance by as much as 10x. You can find the updated connection and cursor limits here.
For existing Amazon DocumentDB clusters, the new capabilities are available today. If you are new to Amazon DocumentDB, the getting started guide will show you how to quickly provision an Amazon DocumentDB cluster and explore the flexibility of the document model.