This master thesis presents relational- and non-relational databases and their features. Nowadays there are variety of different database management systems and the problem is that which one of them is the most rational choice for a new software project. Software project will be bound to this choice it’s whole timeframe and changing it will cost more and more when a project continues. The choices that people make in the beginning of a software project can go easily wrong. There can be a lack of domain specific knowledge or the overall view of the project is blurred.

This thesis will provide a simple instructions what you can follow and make right decisions about database management systems in the beginning of a software project. Research theory is based on relational- and non-relational databases theory. Relational database theory has been created in early 1970 and non-relational database in early 2000. In this thesis I will compare relational and non-relational databases through benchmark tests. Because there is so many different database management systems, I will focus on two products: MySQL and MongoDB. Choice has been made purely based on my knowledge about those products.