Understanding NoSQL

Traditional relational databases allow users to define a strict data structure, and use an SQL-based querying mechanism. NoSQL databases, rather than confining users to define the data structures, allow an open database with which they can store any kind of data and retrieve it by running queries that are not SQL based. In an enterprise, data is generated from all the software used in day-to-day operations. This data has different formats, and bringing in this data for big-data processing requires for a storage system that is flexible enough, to accommodate data with varying data models. The NoSQL database, by design is best suited for such storage.

Note

The CAP theorem or Brewer's theorem talks about distributed consistency. It states that it is impossible to achieve all of the following in a distributed system:

• Consistency: Every client sees the most recently updated data state.

• Availability: The distributed system functions as expected, even if there are node failures...