Re: Improve hash join's handling of tuples with null join keys

> On Mar 19, 2026, at 03:10, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> "Joel Jacobson" <joel(at)compiler(dot)org> writes:
>> I've tested v3-0001 and v3-0002 and can confirm the bug introduced
>> in v3-0001 is fixed in v3-0002:
>
> Thanks for testing!
>
> I noticed from the cfbot that this patch wasn't building anymore.
> nodeHash[join].c now need explicit inclusions of utils/tuplestore.h,
> presumably as a result of Alvaro's recent header-inclusion cleanups.
> Here's a v4 that fixes that; no other changes.
>
> We're getting towards the end of the v19 development cycle, so
> I'm planning to push this soon if there's not objections.
>

I remember I reviewed this patch some time ago, so I revisited v4 today and played with it a bit

Overall, this looks like a solid patch to me.

The only thing I noticed is that while 0002 fixes the tuple-counting issue, there does not seem to be a test that would fail without it. So I think it would be better to add a test case for 0002. I tried doing that and attached a diff. Without 0002, the test fails; with 0002, it passes.

Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/