Abstract: Nowadays the world needs databases to be able to store and process big data effectively and demand for very high-performance when reading and writing. These requirements effects especially in large scale and high concurrency applications such as search engines, hence the traditional database limits itself for such complex requirements. Therefore various types of non-relational databases that are commonly referred to as NoSQL databases which is abbreviation of “Not only Structured Query Language” was emerged. This paper presents a survey on NoSQL and its various data stores. NoSQL (Not Only SQL) is a database which is used to store large amount of data. NoSQL databases are distributed, non-relational, open-source and horizontally scalable. In this paper fundamental concepts like ACID, BASE and CAP theoremwill be described and present a comparison between ACID and BASE properties. Furthermore on the basis ofthe CAP theorem, various forms of data stores in NoSQL like Key/-Value data store, Column family data store, Document data store, Graph database and their characteristics are explained. In addition a taxonomy of NoSQL by various data stores and also the historical trend of popularity of themis presented. At the end, the reasons to consider a NoSQL solution for the Internet of Things data are depicted.
Keywords: NoSQL, ACID, BASE, CAP theorem, Data store, IoT.