Re: Help: Installing 9.6 breaks local connections to 9.2 on Centos 6.9

Magnus Hagander <magnus(at)hagander(dot)net> writes:
> On Tue, May 16, 2017 at 10:00 AM, Devrim Gündüz <devrim(at)gunduz(dot)org> wrote:
>> Not sure whether we should *fix* this or not on RPM side. This may break
>> some of the existing installations, right?

> Changing that in a minor version seems like a *really* bad idea, because
> things *will* break. The way it is now it only breaks in case of a major
> version upgrade, and there is an easy enough workaround present.

Yeah, you don't have a lot of room in a minor release to make changes
that would affect this.

What Red Hat did about this, when I worked there, was to back-port the
unix_socket_directories patch from 9.3 into earlier branches, and then
set up the default server configuration to create sockets in both
/var/run/postgresql and /tmp. But even if you did that, it'd require
an upgrade of the 9.2 installation before it would play nice with a
9.6 libpq, so that might be surprising. (It would also break existing
9.2 installations that were explicitly setting unix_socket_directory,
but we can hope there are very few of those.)

regards, tom lane