Besides the document and atomic operations, Couchbase supports other ways of querying your data: Views, Geo-Spatial Views and N1QL.
Views allow you to provide secondary and composite indexes and transform results using MapReduce. Geo-Spatial Views allow for a query over a geometric range. N1QL is the new SQL-like language for querying documents in Couchbase Server. Both Geo-Spatial Views and N1QL are new in Couchbase Server 4.0