So far, you have understood retrieving documents using the document ID only. However, most of the time, we would like to fetch documents using attributes other than the document ID. In this chapter, we will discuss how to retrieve documents using attributes of documents, when you don't know the document ID before hand. This functionality is provided by a mechanism called MapReduce programming, which is referred to as the term view in the Couchbase terminology. Before diving into views, let's discuss the concepts behind the working of MapReduce (MR) programming, which is the core of views. Hence, understanding it is essential in order to write a view efficiently. We will also discuss the life cycle of a view. Subsequently, we will discuss various features provided by views to filter documents, paginations, grouping, and ordering.

You will also learn how to perform SQL queries in the MapReduce format. You will then learn about various...