I do understand that not everyone may prefer seeing such warnings during PG server restart. To address this, we could introduce a new GUC (perhaps named warn_on_unregistered_guc_prefix), which defaults to false, preserving the existing behaviour. If explicitly enabled, it would emit warnings for these cases, giving users the choice to opt in to this feedback.
Thoughts on this approach?
The need for yet another GUC makes this considerably less appealing than it already is.
I see and agree with the problem statement posed here but would prefer an approach that improves the UX to minimize such mistakes or encourages people to check their settings more easily to ensure that they didn't type 100 when they meant to type 10 for the correct setting name. In short, warning in limited places for a subset of potential errors when doing so involves false positives is just an unappealing change.
