Database management systems are today's most reliable mean to organize data into collections that can be searched and updated. However, many DBMS systems are available on the market each having their pros and cons in terms of reliability, usability, security, and performance. This paper presents a comparative study on the performance of the top DBMS systems. They are mainly MS SQL Server 2008, Oracle 11g, IBM DB2, MySQL 5.5, and MS Access 2010. The testing is aimed at executing different SQL queries with different level of complexities over the different five DBMSs under test. This would pave the way to build a head-to-head comparative evaluation that shows the average execution time, memory usage, and CPU utilization of each DBMS after completion of the test.