Mauri Sahlberg <Mauri.Sahlberg@claymountain.com> writes:
> What if I just wish to move a single database with it's users to a new
> machine? It would be a disaster to overwrite whole existing system
> catalog on the target machine.
Users (and groups) are global across each Postgres installation.
So what you'd need to do is something like this:
pg_dump the desired database, and do "pg_dumpall -g" to get a script
recreating all your users and groups. Edit out the non-pertinent
part of that script. Run the users/groups script and then the pg_dump
script on the target machine.
regards, tom lane