The primary unit of data storage in Couchbase Server 2.1.0 is a JSON document, which is a data structure capable of holding arrays and other complex information. JSON documents are information-rich, flexible structures that enable you to model objects as individual documents. By using JSON documents to model your data, you can construct your application data as individual documents which would otherwise require rigidly-defined relational database tables. This provides storage for your web application which is well suited to serialized objects and the programming languages that use them. Notably in Couchbase Server 2.1.0, as in previous versions of the server, you can also store binary objects, such as integers and strings.
Because you model your application objects as documents, you do not need to perform schema migrations. The documents you use and the fields they store will indicate any relationships between application objects; therefore to update the structure of objects you store, you merely change the document structure that you write to Couchbase Server.
For more information about working with JSON documents and Couchbase, see, Chapter 2, Modeling Documents.