• Large scale data.
• Meeting the scalability and failover.
• Can be used as a Caching layer for storing the transaction data.
Key features of NoSQL are:
• ‘‘Horizontal Scaling/Scaling Out’’ for ‘‘simple operations’’ by
adding more machines to a pool of resources, whereas, ‘‘Vertical
Scaling/Scaling Up’’ means adding more CPU, RAM, etc. to
existing machines.
Scaling Up by adding new expensive big servers is difficult because
of
• Hardware limitations.
• Involves lots of complex Join Operation.
• Requires higher level of skills.
• Not reliable in some cases.
• Replicate/distribute data over many servers.
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:
• Easier deployment.