The introduction of relational database systems helped in faster transactions compared to the existing system for handling structured data. However, in course of time the cost of storing huge volume of unstructured data became an issue in traditional relational database systems. This is where some unstructured database systems like NoSQL databases were introduced in the domain to store unstructured data. This paper focuses on four different structured(PostgreSQL) and un-structured database systems(MongoDB, OrientDB and Neo4j). In this paper, we will eventually see the different kind of data models they follow and analyze their comparative performances by experimental evidences.