What database and mechanisms to use to work with different devices?

Question

Android

I am writing a desktop application in C#. Data processing application - receives and stores data, displays statistics. I also want to write an Android application with the same functionality for mobility. I'm thinking about which database to use so that both programs work with it and are always synchronized.
Tell me please.
PS in Postgresql priority.

Answer 1

The logic, as I understand it, will be processed by the application itself?
In your case with two applications it is not correct.
The application must be only a console (thin client).
All logic for obtaining data (from outside), calculation tasks must be performed on the server.
Clients only send commands and display the result.
If you work with a large amount of data, then you do not need to pull all of them to the client for calculations and send back the results.
Synchronization can be achieved by periodically updating the state of the client, or if the clients communicate via sockets with the server, then the server can notify the client of the changed state instantly.

Answer 2

in Postgresql priority

a good option for a backend (a DBMS on a remote server, which means, for security, at least, it is also covered with an API layer)
if you want a local, the same cross-platform DBMS as the application itself, most likely it is SQLite

Answer 3

It's strange that your question is about the database, and not about the architecture.
What architecture will be?

Answer 4

There is absolutely no difference what the database will be: MySQL, Postgre, MSSQL, or at least Redis or Mongo ...
Since the first step will be to create a web part and write an API.
And already through this API all mobile devices, desktop application and web will work.
PostgreSQL is a good choice

Answer 5

You can use any base you like. And data exchange can be organized through JSON