1. Introduction
NoSQL databases are commercial as well as open source
database management software supporting massive data storage
across distributed servers. Some of the NoSQL support SQL or SQLlike
query language, hence to avoid the misunderstanding that SQL
cannot be used, NoSQL is redefined as ‘‘Not Only SQL’’.
The following three are the major contributors of the NoSQL
movement [1]:
I. BigTable (Google) started in 2004 by Google.
II. Dynamo: Amazon’s Highly Available Key-value Store.
III. CAP theorem.
Lots of commercial and open source NoSQL are developed and
floated in the market by various vendors. Currently there are more
than 150 NoSQL databases.
The common motivations of NoSQL design are: