sorry for stupid question, how REST and database indexes are related?
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.
There is just a lot of anti-patterns floating around because of tightly coupled API / DB's.
People apply this same logic to GQL and get confused.
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.
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.