Re: SLOPE - Planner optimizations on monotonic expressions.

On Fri, May 8, 2026 at 11:19 PM Zsolt Parragi <zsolt.parragi@percona.com>
wrote:

> I found one more corner case with infinities (same applies also with
> negative infinity):
>

This will restrict a lot of cases.


slope_corner_cases.sql enumerate experssions and orders producing
permutations of (-inf, -1, 0, 1, +inf, nan) mapped to (1,2,3,4,5,6)
to visualize other similar corner cases.

Apparently the violations boil down to two cases
* All basic arithmetic operations with infinity constant (with a lucky
exception x - inf)
* Every decreasing function where the index key.
e.g. `-x desc` would have NaNs first

Should I simply detect and disable the above cases?

sqrt(x < 0) already raise an exception, is it safe to assume that for all
the limited domain functions?