On Friday, July 11, 2025, Zhang Mingli <zmlpostgres(at)gmail(dot)com> wrote:
>
> Referring to the SQL 2011 standard, it states that if ORDER BY is
> omitted, the order of rows in the partition is undefined.
> While using a window function without ORDER BY is valid, the resulting
> output seems unpredictable.
>
> So, are both result sets technically correct given the absence of an ORDER
> BY clause?
>
The system is behaving within the requirements of the specification. The
query itself is bugged code that the query author should fix.
David J.