While I don't agree with the conclusion of the article, I still wonder if there's an alternative to SQL that is: - declarative - easy to understand - scales

While I don't agree with the conclusion of the article, I still wonder if there's an alternative to SQL that is: - declarative - easy to understand - scales well with the complexity of the query Perhaps it could look and feel like a functional programming language but underneath uses the same execution engine as SQL I've seen a few attempts at it, but none of them have clicked with me. Thoughts?