Seamus Abshere <seamus@xxxxxxxxxxx> writes: > Should there be a warning for the first query that you reference "tracks" in a subquery but don't use any columns from it? Unfortunately, outer references in subqueries are perfectly legal per SQL standard, and also often essential. If we were to invent a "SET training_wheels = on" option, it would surely include some warnings in this area, although I'm not sure exactly what the triggering conditions ought to be. But there are lots of ways to mess yourself up in SQL; I don't think subqueries are that much worse than some other gotchas. regards, tom lane
