Qualified count star over asymmetric join miscounts

What happens?

A qualified count_star over an asymmetric join will include an erroneous count where there are no matching rows from the joined table.

To Reproduce

create table a (id int4);
create table b (id int4);
insert into a (id) values (1), (2), (3);
insert into b (id) values (2), (3), (3);

select a.id
	, count(*)
	, count(a.*) as a_star
	, count(b.*) as b_star
	, count(b.id) as b_id
from a
left join b on a.id = b.id
group by a.id
;

The last two columns should be equal; the b_star column is erroneous.

OS:

macos

DuckDB Version:

DuckDB v1.4.0-dev3790 (Development Version) 879df8212b

DuckDB Client:

duckdb cli

Hardware:

No response

Full Name:

Tim McEwan

Affiliation:

Climate Risk

What is the latest build you tested with? If possible, we recommend testing with the latest nightly build.

I have tested with a nightly build

Did you include all relevant data sets for reproducing the issue?

Yes

Did you include all code required to reproduce the issue?

• Yes, I have

Did you include all relevant configuration (e.g., CPU architecture, Python version, Linux distribution) to reproduce the issue?

• Yes, I have