Right, I understand why you'd want to project at the very end of the query, i.e. suppress some columns from being shown. Other than that, I don't see the point, unless there's a performance impact. Keeping columns around doesn't actually change the result of the query in any way.
You've definitely missed the point because you're concerned about the "very end of the query". I'm describing both a reporting and more importantly as far as I'm concerned an explorative process that's disrupted by the silly need to list out all columns. Performance is irrelevant.
Yes, I know I've missed the point. That's why I asked my question in the first place! My question was:
> What's the use case for that? In fact, I can hardly understand the benefit of projecting at all, except at the very end. Why would you want to do it? Is there a performance benefit?
and I meant it literally. It's not an oblique, rhetorical way of saying "you don't need to do this". It was a genuine question!
You've answered that it's convenient when doing exploratory work. Thank you. That helps me understand better.
