Re: Yet another failure mode in pg_upgrade

Bruce Momjian <bruce@momjian.us> writes:
> My point is that we are still going to need traditional connections for
> live checks.

Yes, but that's not terribly relevant, IMO.  All it means is that we
don't want to invent some solution that doesn't go through libpq.

> If we could find a solution for Windows, the socket in
> current directory might be enough to lock things down, especially if we
> put the socket in a new subdirectory that only we can read/write to. 

Who is "we"?  Somebody else logged in under the postgres userid could
still connect.

> Should I persue that in my patch?

I think this is just a band-aid, and we shouldn't be putting more
effort into it than needed to ensure that unexpected configuration
settings won't break it.  The right fix is a better form of
standalone-backend mode.  Maybe I will go pursue that, since nobody
else seems to want to.
        regards, tom lane