Re: Wrong results with grouping sets

On Fri, May 17, 2024 at 5:41 PM Richard Guo <guofenglinux(at)gmail(dot)com> wrote:

> I've spent some more time on this patch, and now it passes all the
> regression tests. But I had to hack explain.c and ruleutils.c to make
> the varprefix stuff work as it did before, which is not great.
>

I've realized that I made a mistake in the v4 patch: If there are join
alias vars in the targetlist and HAVING clause, we should first flatten
them before replacing the grouped variables involved there with
grouping-RTE Vars. To fix this issue, I decide to merge the newly added
function substitute_group_exprs into check_ungrouped_columns by changing
check_ungrouped_columns to also perform the replacement, which is Tom's
initial suggestion I think.

Now it seems that 'check_ungrouped_columns' is no longer an appropriate
name for the function. So I rename it to 'substitute_grouped_columns'.
But I'm open to other names if there are any suggestions.

I've also worked on the comments.

Thanks
Richard