Apache Open Source Project--couchdb

Apache CouchDB is a document-oriented database management system. It provides a REST interface with JSON as a data format to manipulate it and can manipulate the organization and rendering of documents through views. CouchDB is the top open source project of the Apache Foundation.

COUCHDB implementation to the bottom of the data structure is two types of b+tree.

Unlike today's popular relational database servers, CouchDB is organized around a series of semantically self-contained documents. Documents in CouchDB are modeless (schema free), which means that the document does not require a particular structure. This characteristic of CouchDB has its own scope of application relative to the traditional relational database. In general, apps built around documents are better suited to use CouchDB as their back-end store. CouchDB emphasizes that the documents stored therein are semantically self-contained. This approach to document-oriented design is more closely related to the real situation of many application problem domains. For this type of application, it is more natural and simple to use CouchDB documentation for modeling. At the same time, CouchDB also provides a view of the MapReduce programming model to query documents, providing the ability to resemble SQL statements in relational databases. CouchDB provides a better alternative to relational databases for many applications.

Apache Open Source Project--couchdb