I just noticed that there doesn't seem to be any good way of finding out what a postmaster's default value of unix_socket_directory is. If you try to SHOW it you just get an empty string. We could probably fix things so that SHOW exposes the actual setting, but (1) there might be security arguments against that, and (2) if your problem is that you would like to find out the value so's you can connect to said postmaster, SHOW isn't going to help you.
One possible response would be to add an item to what pg_config knows about, eg "pg_config --socketdir". This doesn't answer every possible use-case either, but it would be helpful for some scenarios. Thoughts? regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers