Why is database design so important?
The modern database‑and‑applications development software is so easy to use that many people can quickly learn to implement a simple database and develop simple applications within a week or so, without giving design a thought. As data and reporting requirements become more complex, those same people will simply (and quickly!) produce the required add-ons. That’s how data redundancies and all their attendant anomalies develop, thus reducing the “database” and its applications to a status worse than useless. Good applications can’t overcome bad database designs. The existence of a DBMS does not guarantee good data management, nor does it ensure that the database will be able to generate correct and timely information. Ultimately, the end user and the designer decide what data will be stored in the database. Since most current DBMSes are based on the relational model, the relational model’s conceptual simplicity could be compared to the hierarchical and network models. Because the entity
