Views

In Apache CouchDB, a view is a queryable index that enables efficient access to data in a database. Views are defined using MapReduce functions, which take documents from the database and map them to key-value pairs. These key-value pairs are then reduced to produce the final view output.

Views can be created on any subset of data in a database, and can be filtered and sorted according to specific criteria. Views can also be updated incrementally as new documents are added to or deleted from the database, making them an efficient way to access and analyze data in CouchDB.

Views are particularly useful in applications that require complex queries or data analysis, such as analytics dashboards or reporting tools. They can also be used to implement search functionality, by indexing specific fields in documents and enabling full-text search queries.

Overall, views are a powerful feature of Apache CouchDB that enable efficient and flexible access to data in a database.