Re: [Question] Window Function Results without ORDER BY Clause

"David G. Johnston" <david.g.johnston@gmail.com> writes:
> On Friday, July 11, 2025, Zhang Mingli <zmlpostgres@gmail.com> wrote:
>> 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.

Well, it's our own regression-test query.  I think the actual question
being asked here is "do our regression tests need to pass under random
non-default GUC settings?".  I'd say no; it'd be next door to
impossible to guarantee that.  If this query gave unstable results
in practice, we'd have noticed by now (it's been there since 2010).

            regards, tom lane