On Tue, Dec 19, 2023 at 11:22 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
Richard Guo <guofenglinux@gmail.com> writes: > On Tue, Dec 19, 2023 at 12:08 PM Tom Lane <tgl@sss.pgh.pa.us> wrote: >> Thanks for looking! Do you have an opinion about the int64-vs-double >> question?
> To be honest, I don't have a preference on which one is better. I think > double is good enough for now as we don't need to worry about overflow > with it.
After sleeping on it, I'm coming around to the idea that int64 will be better. The argument that convinces me is that using int64 provides a datatype-based clue that we are working with a width and not a row count, cost, or selectivity number. I don't feel a need to go as far as invent a typedef alias like Cardinality; but plain "double" in the planner tends to be a rowcount estimate, which is not what we want people to think of.
Fair point.
I'll make that change and push it.
Thanks for the change and pushing!
BTW, I think it's sufficient to fix this in HEAD. The troublesome example seems quite artificial to me, and we've not heard field reports suggesting that people have had real problems here.
