The basic difference between the Aggregate oriented database and Non-aggregate databases is that Aggregate Oriented database splits relations. The common feature is that both the Aggregate Oriented and Non-aggregate Oriented NoSQL are Schema-Less. Now, the above mentioned NoSQL and their underlying data storage format are briefly discussed.
(a) Key/value databases The key-value stores are commonly known as dictionaries or hash. In NoSQL key-value stores have been adopted because they promote easy scalability and flawless growth at rapid speed. The basic concept is that a globally distributed hash table has keys that lead to the different database servers scattered all over the world. Each data item is converted into a key using some unique formula which is stored in the lookup table or directory. When the data are needed, the key is converted into the location of the data and accordingly data are retrieved.