If present. And for that they need to be created, and which are the right ones is less obvious when working higher in the abstraction staircase.
> It doesn't make a difference. How could it?
Because the SQL generated by ORMs can be wildly stupid in many cases. Here's one blogpost with an example, where regular SQL and query builder that maps to SQL almost directly generate a decent query on a simple relation, while a full ORM does something stupid: https://blog.logrocket.com/why-you-should-avoid-orms-with-ex...
GraphQL allows you to specify what data you need. Obviously, if you use some middleware which throws this information away and just fetches everything from the database, then you have an inefficient system. But this is not a problem inherent to GraphQL or generated SQL in general.
And the whole point of GraphQL is that you specify exactly what data you need, so overfetching is avoided. This is in contrast to traditional REST API's where you get a fixed resource.