CouchDB
 |
|
CouchDB's Futon Administration Interface, User database
|
|
| Original author(s) | Damien Katz, Jan Lehnardt, Noah Slater, Christopher Lenz, J. Chris Anderson, Paul Davis, Adam Kocoloski, Jason Davies, Benoît Chesneau, Filipe Manana, Robert Newson |
|---|---|
| Developer(s) | Apache Software Foundation |
| Initial release | 2005 |
| Stable release |
2.0.0 / September 20, 2016
|
| Preview release |
2.0rc4 / August 12, 2016
|
| Repository | github |
| Development status | Active |
| Written in | Erlang |
| Operating system | Cross-platform |
| Type | Document-oriented database |
| License | Apache License 2.0 |
| Website | couchdb |
Apache CouchDB is open source database software that focuses on ease of use and having an architecture that "completely embraces the Web". It has a document-oriented NoSQL database architecture and is implemented in the concurrency-oriented language Erlang; it uses JSON to store data, JavaScript as its query language using MapReduce, and HTTP for an API.
CouchDB was first released in 2005 and later became an Apache Software Foundation project in 2008.
Unlike a relational database, a CouchDB database does not store data and relationships in tables. Instead, each database is a collection of independent documents. Each document maintains its own data and self-contained schema. An application may access multiple databases, such as one stored on a user's mobile phone 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.
CouchDB implements a form of multiversion concurrency control (MVCC) so it does not lock the database file during writes. Conflicts are left to the application to resolve. Resolving a conflict generally involves first merging data into one of the documents, then deleting the stale one.
Other features include document-level ACID semantics with eventual consistency, (incremental) MapReduce, and (incremental) replication. One of CouchDB's distinguishing features is multi-master replication, which allows it to scale across machines to build high performance systems. A built-in Web application called Futon helps with administration.
Couch is an acronym for cluster of unreliable commodity hardware. The CouchDB project was created in April 2005 by Damien Katz, former Lotus Notes developer at IBM. He self-funded the project for almost two years and released it as an open source project under the GNU General Public License.
...
Wikipedia