NoSQL Database Types

NoSQL refers to a class of non-relational databases and, by itself, the term means little because there are different kinds of NoSQL databases. It’s like using the term NoRED colors to refer to any of Green, Blue, Yellow, Orange… you get the idea.

NoSQL databases can be identified as Key-Value stores, Wide-Column stores, Graph stores, and Document stores. Each comes with it’s own set of merits and demerits and has their place. For example, key-value storage systems are commonly used for caching and session information; they scale easily but have limited quering capabilities. Wide column storage systems are great for analytical workloads, such as to get the total sales for a range of dates. Graph databases provide rich querying capabilties when we are interested in the relationships between entities. Finally, document stores are used to store related data together - perfect for driving down query time when you frequently need to fetch related data together.