Peter Eisentraut <peter_e@gmx.net> writes:
> I'm concerned that we leave essentially no migration path, that is, the
> ability to turn the feature on to try it out without immediately breaking
> every application.
Uh ... what? I fail to understand your objection. AFAICS the only
apps that could be "broken" are scripts that have usernames hardwired
into them ...
regards, tom lane