Re: new --maintenance-db options

Excerpts from Robert Haas's message of lun jun 25 14:58:25 -0400 2012:
>
> On Mon, Jun 25, 2012 at 2:49 PM, Alvaro Herrera
> <alvherre(at)commandprompt(dot)com> wrote:
> > Excerpts from Robert Haas's message of lun jun 25 11:57:36 -0400 2012:
> >> Really, I think
> >> pg_upgrade needs this option too, unless we're going to kill the
> >> problem at its root by providing a reliable way to enumerate database
> >> names without first knowing the name one that you can connect to.
> >
> > I think pg_upgrade could do this one task by using a standalone backend
> > instead of a full-blown postmaster.  It should be easy enough ...
>
> Maybe, but it seems like baking even more hackery into a tool that's
> already got too much hackery. It's also hard for pg_upgrade to know
> things like - whether pg_hba.conf prohibits access to certain
> users/databases/etc. or just requires the use of authentication
> methods that happen to fail. From pg_upgrade's perspective, it would
> be nice to have a flag that starts the server in some mode where
> nobody but pg_upgrade can connect to it and all connections are
> automatically allowed, but it's not exactly clear how to implement
> "nobody but pg_upgrade can connect to it".

Well, have it specify a private socket directory, listen only on that
(not TCP), and bypass all pg_hba rules.

--
Álvaro Herrera <alvherre(at)commandprompt(dot)com>
The PostgreSQL Company - Command Prompt, Inc.
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