On Mon, Jan 26, 2026 at 12:44 AM Tom Lane <[email protected]> wrote: > > David Rowley <[email protected]> writes: > > On Sun, 25 Jan 2026 at 19:48, Junwang Zhao <[email protected]> wrote: > >> In [1], David Rowley noted that COUNT(NULL) can be replaced > >> with '0'::bigint. The change should be straightforward, and I came > >> up with the attached patch to implement it. > > > Coming up with the code to do this wasn't the problem. I already > > posted it in the patch in [2]. The reason I didn't commit that part is > > simply that I don't think anyone would ever write COUNT(NULL) in a > > query. > > Yeah, I agree that this should be so rare as to not be worth expending > planner cycles to check for, not to mention future code maintenance > costs. The other special cases we optimize COUNT() for are common > real-world usages, but not this.
Agreed, good to know, thanks for the explanation. > > regards, tom lane -- Regards Junwang Zhao
