I'm finding test cases like this: > ~~~ SELECT group_concat(word,',') FROM (SELECT word FROM dictionary ORDER BY 1); ~~~ The idea here is that you want to feed the values into group_concat() in a specific order. The ORDER BY clause in the subquery is used to impose that order. Now, I don't think the SQL language ever guarantees an order in this particular circumstance. So, technically, we should be free to ignore the ORDER BY clause in the subquery above. But I'm wondering how often this kind of thing occurs in the wild, and how many applications will break if I add an optimization to ignore (technically) useless ORDER BY clauses in subqueries? If you had an application that has been working great for 10 years and then starts giving incorrect answers when you upgrade to SQLite 3.37.0, would you be pleased? In order to move forward with this optimization, I need to be convinced that it will be a net positive. I need evidence that the benefit of increased performance will outweigh the cost of fixing applications that break because they were depending on undocumented behavior. I'm not yet convinced that the benefits exceed the inconvenience in this case, but I'm open to arguments to the contrary.