Re: Should IGNORE NULLS cache nullness for volatile arguments?

> On May 14, 2026, at 20:56, Tatsuo Ishii <ishii(at)postgresql(dot)org> wrote:
>
> Hi Chao,
>
>>> The attached patch makes a small change in that direction. It only uses the IGNORE NULLS nullness cache when the argument is safe to reuse. For non-cacheable arguments, the nullness is treated as unknown and the argument is evaluated again.
>>>
>>> See the attached patch for details.
>>
>> I will look into the patches.
>
> @@ -3454,7 +3455,10 @@ ignorenulls_getfuncarginframe(WindowObject winobj, int argno,
> if (isout)
> *isout = false;
>
> - v = get_notnull_info(winobj, abs_pos, argno);
> + if (winobj->notnull_info_cacheable[argno])
>
> What about moving this if statement inside get_notnull_info() so that
> the caller does not care about this argno is cacheable or not?
>
> + /* record the row status if it is safe to reuse */
> + if (winobj->notnull_info_cacheable[argno])
> + put_notnull_info(winobj, abs_pos, argno, *isnull);
>
> Similary, we can move "if (winobj->notnull_info_cacheable[argno])" inside put_notnull_info().
>

Yep, good idea. Addressed in attached v2.

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