Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> I'm not talking about changing the default, just having it be possible
> to use \password with the new system as it was with the old, whatever
> exactly we think that means.
Seems to me the intended behavior of \password is to use the best
available practice. So my guess is that it ought to use SCRAM when
talking to a >= 10.0 server. What the previous password was ought
to be irrelevant, even if it could find that out which it shouldn't
be able to IMO.
regards, tom lane