Friday, 28 October 2011

NoSQL database- What is it?

These are following some of very famous NoSQL database.

  • Dynamo: Dynamo is created by Amazon and is the most prominent Key-Value NoSQL database. Amazon developed dynamo when they were in need of a highly scalable distributed platform for their e-commerce businesses.
  • Cassandra: Cassandra is open sourced developed by Facebook and is a columnar  NoSQL database.
  • BigTable: BigTable is Google's proprietary columnar oriented database.
  • SimpleDB: SimpleDB is another database developed by Amazon.
  • CouchDB: CouchDB along is open source document oriented NoSQL databases.
  • Neo4J: Neo4j is an open source graph database.

One method to define NoSQL is to consider what its not. It's not SQL and it's not relational. Like the name suggests, it's not a substitute for a RDBMS but compliments it. NoSQL is designed for scattered data stores for very huge scale data needs. Think about Facebook with its 500,000,000 users or Twitter which accumulates Terabits of data every single day.
In a NoSQL database, there is no joins and no fixed schema . A RDBMS "scales up" by getting faster and quicker hardware and adding memory. NoSQL, on the other hand, can take advantage of "scaling out". Scaling out refers to scattering the load over many commodity systems. This is the component of NoSQL that makes it an reasonably priced solution for bulky datasets.