David Rowley <dgrowle...@gmail.com> writes: > Aside from that, I don't have any ideas on how to get rid of the > possible additional datumCopy() from non-Var arguments to these window > functions. Should we just suffer it? It's quite likely that most > arguments to these functions are plain Vars anyway.
No, we shouldn't. I'm pretty sure that we have various window functions that are deliberately designed to take advantage of the no-copy behavior, and that they have taken a significant speed hit from your having disabled that optimization. I don't say that this is enough to justify reverting the chunk header changes altogether ... but I'm completely not satisfied with the current situation in HEAD. regards, tom lane