Database management systems are an integral part of ICT infrastructure in contemporary companies. Their performance is imperative for the company to becompetitive. Thus, knowing how to develop efficient database applications and to be able to measure their performance and optimise them is a crucial asset for any application developer. In this master?s thesis a special emphasis is put on Oracle as it is a widely used database management system with a good array of optimisation techniques and tools. This master?s thesis examines database optimisation first on a theoretical level and then the optimisation and performance measurement techniques are tested in practice in a laboratory experiment. In this constructive part an Oracle PL/SQL procedure is optimised by using bulk processing techniques, applying better transaction handling and using dynamic SQL.