Should the data model on the client and server be identical?

Question

Mobile development

When working with a server, does the mobile application have to have exactly the same database structure as on the server? Relationships between tables naturally need different ones, since there is one user in the application, and there are many on the server, and then some of the tables are redundant for the client.

Answer 1

The client and server are 2 separate applications, respectively, choose the model that suits you best. The only point is that it is often convenient to use identical models in order to write less repetitive code, well, it turns out to be a little easier in support (perhaps).
Another option is to use a simplified model, throw out unnecessary fields, but leave those that intersect. This may make it easier for you to keep the diagram in your head.
In general, do what is more convenient for you.

Answer 2

Depends on the complexity of the application model and/or how the data is passed: generally not necessary, but if you stick to DDD and/or use an ORM, it's much easier if the models match.