It would be really handy to know that `$1` is being used as a non nullable value, while `$2` could actually be null. Can this already be achieve today, or would there be a way to surface this kind of information for query parameters in the extended protocol?
There is no attempt in the system to try and pass constraint information through the query planner and expose it to the client. It doesn’t seem like there is sufficient utility to try and do so. The fact that it pretty much only works in the exact query form you’ve shown here is part of that. Not sure we’d turn it down but someone will need to step up and scratch their own itch in all likelihood (the request for similar functionality in the result comes up too).
David J.
