Re: Allow WindowFuncs prosupport function to use more optimal WindowClause options

Erwin Brandstetter <brsaweda@gmail.com> writes:
> I am thinking of building a test case to run
> - all existing window functions
> - with all basic variants of frame definitions
> - once with ROWS, once with RANGE
> - on basic table that has duplicate and NULL values in partition and
> ordering columns
> - in all supported major versions

> To verify for which of our window functions ROWS vs. RANGE never makes a
> difference.
> That should be obvious in most cases, just to be sure.

> Do you think this would be helpful?

Doubt it.  Per the old saying "testing can prove the presence of bugs,
but not their absence", this could prove that some functions *do*
respond to these options, but it cannot prove that a function
*doesn't*.  Maybe you just didn't try the right test case.

If you want to try something like that as a heuristic to see which
cases are worth looking at closer, sure, but it's only a heuristic.

            regards, tom lane