NoSQL databases are often compared by various non-functional criteria, such as scalability, performance, and consistency. This aspect of NoSQL is well-studied both in practice and theory because specific non-functional properties are often the main justification for NoSQL usage and fundamental results on distributed systems like the CAP theorem apply well to NoSQL systems. At the same time, NoSQL
![NoSQL Data Modeling Techniques](https://cdn-ak-scissors.b.st-hatena.com/image/square/e01a769d9e142d92d93480ac4b80f38470901585/height=288;version=1;width=512/https%3A%2F%2Fhighlyscalable.files.wordpress.com%2F2012%2F02%2Foverview2.png)