On Mon, Jun 13, 2005 at 12:22:14 -0400, Tom Lane <[EMAIL PROTECTED]> wrote: > > I don't think the use-case has been shown that justifies doing this much > work to ignore useless ORDER BY clauses. The examples that have come up > in the past all suggest ignoring index columns not the other way 'round. > Can you make a case that we need to do that part of it?
I don't think so. I don't think people are likely to order by constant expressions except by adding them to the front to help optimization. When I was thinking about this I was looking at what equivalences could be used and didn't look back to see which ones would be useful in the normal case. And I think it is a lot more likely people will leave out columns they know not to be relevant than to include them. ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org