From the point of view of you the database user, you the guy that sets up the database, that creates the SQL, that does "sudo apt install postgres", it's simple

From the point of view of you the database user, you the guy that sets up the database, that creates the SQL, that does "sudo apt install postgres", it's simple. Could you repair the little Briggs and Stratton in your lawnmower? Almost certainly. You can easily hold a mental model of how it all works in your mind, and diagnose and repair any fault. Could you actually design such an engine? Where would you start?