Re: Support custom socket directory in pg_upgrade

Daniel Gustafsson <daniel(at)yesql(dot)se> writes:
>> On 7 Nov 2018, at 08:23, Peter Eisentraut <peter(dot)eisentraut(at)2ndquadrant(dot)com> wrote:
>> Why not always create a temporary directory and put it there. Then we
>> don't need an option. It's not like the current directory is a
>> particularly good choice anyway.

> I agree that cwd isn’t a terribly good default, but is there a good way to
> identify a suitable temporary directory to use across all platforms (mostly
> thinking about Windows)?

Windows isn't a problem because it doesn't do Unix-style sockets anyway.
However, I agree that Peter's proposal is just begging the question of
how we'd identify a better default choice than cwd.

Also, even if we had an arguably-better idea, I suspect that there would
always be cases where it didn't work. For example, one idea is to make
a temporary directory under the installation's normal socket directory
(thus, /tmp/pgXXXX/ or some such). But, if the normal socket directory
is not /tmp, we might find that pg_upgrade can't write there.

So I'm inclined to think that a --socketdir option is a reasonable
feature independently of whether someone comes up with a different
proposal for the default location.

regards, tom lane