Main-memory database VS Traditional database

There has been a surge of new databases in recent years. Applications today create a higher demand on database performance than ever before. Main-memory databases have come into the market quite recently and they are just now catching a lot of interest from many different directions. Main-memory databases are a type of database that stores all of its data in the primary memory. They provide a big increase in performance to a lot of different applications. This work evaluates the difference in performance between two chosen candidates. To represent main memory databases we chose VoltDB and to represent traditional databases we chose MySQL. We have performed several tests on those two databases. We point out differences in functionality, performance and design choices. We want to create a reference where anyone that considers changing from a traditional database to a main memory database, can find support for their decision. What are the advantages and what are the disadvantages of using a main-memory database, and when should we switch from our old database to a newer technology