Re: Multiple postgresql installations on one machine.

Charles Tassell <ctassell(at)isn(dot)net> writes:
> I may be wrong, but I don't think it's possible to have them on the same
> port. The problem is that the TCP/IP port defaults to the same as the UNIX
> sockets port, and UNIX sockets are local to the machine, so they are
> completely independent of IP addresses and can not be duplicated.

Unix sockets need to have unique pathnames in the local filesystem.
The PG "port number" is actually only a component of the file name.
So all you need to do if you need to have conflicting port numbers
is to vary the unix_socket_directory parameter for each postmaster.

However, varying the port number is probably a simpler attack...

>> I can't seem to tell psql where to find the moved unix socket.

Use -h /path/to/directory/containing/socket. AFAIR you can set the
path in PGHOST environment variable, if that helps.

regards, tom lane