NoSQL encompasses a wide variety of different database technologies and were developed in response to a rise in the volume of data stored about users, objects and products, the frequency in which this data is accessed, and performance and processing needs. Relational databases, on the other hand, were not designed to cope with the scale and agility challenges that face modern applications, nor were they built to take advantage of the cheap storage and processing power available today.
Big Data Explained
Big Data refers to technologies and initiatives that involve data that is too diverse, fast-changing or massive for conventional technologies, skills and infra- structure to address efficiently. Said differently, the volume, velocity or variety of data is too great. But today, new technologies make it possible to realize value from Big Data.
Hadoop is a software technology designed for storing and processing large volumes of data using a cluster of commodity servers and commodity storage. Hadoop is an open-source Apache project started in 2005 by engineers at Yahoo. It consists of a distributed file system, called HDFS, and a data processing and execution model called MapReduce.