What happens?

The corr aggregate should return NaN when a column is constant, not NULL, same as 0 / 0 returns NaN not NULL anymore since v1.1.

EDIT: can't check right now but it should be verified if the same issue exists for regr_slope

To Reproduce

SELECT 
    corr(x, x)
FROM
    (SELECT 1 AS x UNION ALL SELECT 1 AS x);

┌────────────┐
│ corr(x, x) │
│   double   │
├────────────┤
│       NULL │
└────────────┘

OS:

Linux

DuckDB Version:

1.1.0

DuckDB Client:

Python

Hardware:

x64

Full Name:

Soeren Wolfers

Affiliation:

G-Research

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?

Not applicable - the reproduction does not require a data set

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