Apache CouchDB is a document oriented database management system. It provides a REST interface with JSON as the data format to operate on it, and can manipulate the organization and presentation of documents through views. CouchDB is the top open source project of the Apache Foundation.
The data structures implemented by CouchDB to the lowest level are two types of B+Tree.
Unlike today's popular relational database servers, CouchDB is organized around a series of semantically self contained documents. The documents in CouchDB have no schema free, that is, they are not required to have a specific structure. This feature of CouchDB makes it applicable to traditional relational databases. Generally speaking, applications built around documents are more suitable for using CouchDB as their background storage. CouchDB emphasizes that the documents stored in it are semantically self contained. This document oriented design idea is closer to the real situation of the problem domain of many applications. For such applications, it will be more natural and simple to use CouchDB documents for modeling. At the same time, CouchDB also provides a view based on MapReduce programming model to query documents, which can provide the ability similar to SQL statements in relational databases. CouchDB provides a better choice than relational databases for many applications.
JDBC driver for CouchDB—— jcouchdb