Built-in reduce functions
Often, we want to perform summarized/aggregate operations on data, such as count or grouping of documents by some attributes and using it to report or get statistics about some documents. This kind of grouping of data or documents takes place in the reduce function of the view. For example, we want to find the total number of users in our LearningCouchbase bucket, the total number of skill sets by the user, and so on. The reduce() function will reduce an array of values emitted by the corresponding map() function. Couchbase ensures that the reduce function is applied to each record of the input parameter, and the returned value is the result of the view. The output of the reduction is stored along with the view information. There are three in-built reduce functions provided by Couchbase out-of-the-box.
count
The count function is used to count the number of documents emitted by the map function. You need to set the reduce parameter equal to true to use the reduce...