CouchDB is a document-oriented database that is built for the web, open source, and written in Erlang. It has no schema, uses HTTP as its protocol, supports eventual consistency through multiversion concurrency control, and models transactions through documents. CouchDB is designed for crash-only recovery, allows for automated replication between distributed nodes, and enables long-polling queries through requests that can remain open indefinitely.

1. CouchDB Giorgio Sironi Politecnico di Milano, #764852 Polo di Como – 18/01/2011

2. Characteristics Cluster Of Unreliable Commodity Hardware

3. Document-oriented

4. Built for the web

5. Open source, written in Erlang

6. Here is a document No schema, no atomic values, no sequential keys

7. No binary protocol HTTP is universal and firewall-friendly

8. No SQL (really no-brainer)

9. No immediate consistency ”Stale” views, but multiversion concurrency control

10. No transactions A transaction is modelled with a document