What is "couchdb"

Apache Couchdb, commonly referred to as Couchdb, is an open-source database that focuses on ease of use and the philosophy of being "a database that spans the Web". It is a non-relational database (Nosql) that uses JSON to store the data, Javascript as its query language using Mapreduce, and HTTP as API. One of its striking features is the ease of replication.

Unlike a relational database, Couchdb does not store data and relationships in tables. Each database is a collection of independent documents, and each document maintains its own data and schematics. An application can access multiple databases, for example, on the user’s smartphone and another on a server. Document metadata contains revision information, making it possible to merge any differences that may have occurred while the databases were disconnected.

Its characteristics are ACID semantics with eventual consistency, Mapreduce, incremental replication and fault tolerance. Administration is supported with a built-in web application called Futon.

Link to official page: http://couchdb.apache.org/

Bibliographic References:

• Anderson, J. Chris; Slater, Noah; Lehnardt, Jan (November 15, 2009), Couchdb: The Definitive Guide (1st ed.), O'Reilly Media.
• Brown, MC (October 31, 2011), Getting Started with Couchdb (1st ed.), O'Reilly Media, pp. 50.