7. Conclusion

Database optimization begins at the design stage and continues throughout the application's lifecycle. The first step is to choose the right system architecture, which must reflect the context and needs of the application. The choice of data model has a major impact on the accuracy of the representation of real-world information, and above all on the scalability of the application. Finally, it is important to determine the most frequent and costly queries, in order to define the most appropriate access methods. While it is difficult to modify the architecture or change the data model once the application is in place, it is possible to define new access methods or modify them as the application evolves.

DBMS provide high-performance query optimizers. These are tried-and-tested programs, which have required considerable development resources (around 50 man-years to...