Result from first window function reused by other window functions

[knutwannheden]

It looks like when a query contains multiple window functions, that the result evaluated by the first window function will also be returned by the other window functions. Take this example:

create table t(a int, b int);
insert into t(a, b) values (1, 1), (1, 2), (1, 3), (2, 4), (2, 5), (2, 6);

select a, b, sum(b) over (order by b) total_sum, sum(b) over (partition by a order by b) a_sum
from t
order by 1, 2;

In the result set the last two columns always contain the same value, while they clearly should not (compare against https://www.db-fiddle.com/f/pQav68zxdV4gnRjcaoXdrm/0).

[fulghum]

Hey Knut, thanks for reporting this one. This definitely looks like a bug where Dolt is not returning the same data as MySQL.

Thanks for the good repro case; we'll dig in and see what we can find.

[fulghum]

Quick update... I started repro and debugging through this one on Friday and it's top of my stack today. I'll keep you updated on today's progress.

[knutwannheden]

Thanks for looking into this!

[fulghum]

My pleasure! This is a fun one to debug through. I had a few other meetings and reviews today, but still made some progress on this one. I found what I suspect is a simpler repro case (but could end up being a separate issue). I've got a lot more time available tomorrow to keep focused on this one and will keep you updated.

[fulghum]

Hey Knut, just following up... I needed to prioritize a couple of issues this week for customers with support contracts, so that preempted this work. It's still on my radar though, and we'll get back to it.

[PavelSafronov]

@knutwannheden Thanks again for the report. I've just merged a fix for this issue. It should make it into the dolt executable some time next week.