Riak – A Scalable Web Database

Riak was specially designed for master-less replication from the GET-go where all the nodes participate equally in the replication and adding new servers to join the party (scaling horizontally).
Riak supports “link-walking” powerful than any other traditional relational DB joins.

Every relatrions stored in Riak have one-way relationships to the other data via the Link HTTP header.
 
Riak is a document based database that provides a REST interface, where you don’t bother to write any Erlang code.

Riak allow you to define N, R and W value for each operation and these values are:
• N: the number of replicas of each value to store
• R: the number of replicas required to perform a read operation
• W: the number of replicas needed for a write operation

Riak is also one of the key/value store that takes the responsibility of simplifying development by giving developers an ability to prototype, test, and deploy their applications.
In this particular application you can the database is build on three aspects and they are:

• A Database Built for the Web
A Database Built for Scale
• A Database Built to Ease Operations
Riak provide a database that suits for Web applications by combining three major features and they are:
• A decentralized key/value store,
• A flexible map/reduce engine, and
• A friendly HTTP/JSON query interface.