They're not really related here. The premise of my question is more around the fact that with REST, which database queries you'll run are fairly static and are known by the backend based on what APIs they expose. Therefore it's easy (ish) to make sure said queries are indexed properly.
With GraphQL, I'm asking about how clients _could_ write arbitrary requests, that since the backend doesn't know about them ahead of time, can't optimize for with indexes.
And programmers will apply this same anti-pattern to GQL, so it doesn't really solve that problem, and arguably makes it worse for the reasons stated in the un-indexed field example.
And that is why you used gql codegen and typing to limit their capability to do so.
Part of the benefit of gql that people often overlook is its self documenting nature and when tied with automation tools its ability to provide a lot of flexibility for developers without compromising you db.
The gql server is ultimately what is responsible for this, and we use schema introspection to ensure the searchable / sortable fields are only exposed if indexed.
