Re: -Wformat-zero-length

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Peter Eisentraut <peter_e@gmx.net>
Cc: Dimitri Fontaine <dimitri@2ndQuadrant.fr>, Alvaro Herrera <alvherre@2ndquadrant.com>, Bruce Momjian <bruce@momjian.us>, Robert Haas <robertmhaas@gmail.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2012-08-14T21:56:39Z
Lists: pgsql-hackers
Peter Eisentraut <peter_e@gmx.net> writes:
> On 8/10/12 7:48 PM, Dimitri Fontaine wrote:
>> What about having single user mode talk fe/be protocol, and talk to it via a UNIX pipe, with pg_upgrade starting the single user backend as a subprocess?

> I think that's essentially equivalent to starting the server on a 
> Unix-domain socket in a private directory.  But that has been rejected 
> because it doesn't work on Windows.

> The question in my mind is, is there some other usable way on Windows 
> for two unrelated processes to communicate over file descriptors in a 
> private and secure way?

You're making this unnecessarily hard, because there is no need for the
two processes to be unrelated.

The implementation I'm visualizing is that a would-be client (think psql
or pg_dump, though the code would actually be in libpq) forks off a
process that becomes a standalone backend, and then they communicate
over a pair of pipes that were created before forking.  This is
implementable on any platform that supports Postgres, because initdb
already relies on equivalent capabilities.

			regards, tom lane