Do you have to design databases from scratch or improve existing ones?

In the practice of a systems analyst and database developer, both options are encountered: designing databases from scratch and refining existing ones.

If the project is new, it is often necessary to design a database from scratch, taking into account requirements, business logic, and expected loads. This includes modeling entities, relationships, and data normalization.

In the case of supporting or developing existing systems, one has to work with an already existing database — optimizing the structure, adding new tables, modifying schemas, and migrating data. This requires understanding the current architecture and being careful not to disrupt the application's operation.

Thus, experience in both designing new projects and refining existing databases is very important.