How do I rename the default postgres superuser to “root”?

Question

I currently log in to PostgreSQL using psql -U postgres. How do I rename postgres user to root?

If I am already logged in as postgres then trying ALTER USER postgres RENAME TO root will say ERROR: session user cannot be renamed.

Is it possible to rename the user without logging as postgres user? I don't think I have any other superuser since this is a fresh install of PostgreSQL.

By the way, I am running Gentoo on Amazon EC2.

Answer 1

You should be able to just create a new postgres superuser called root by logging in as the postgres user and (at the shell) typing;

createuser --superuser root
psql> create database root owner root

After that, when logged in as root, you should be able to do what you want with the postgres user.

Answer 2

What about:

ALTER ROLE postgres RENAME TO root;

using a different superuser role?

Answer 3

You can try

update pg_authid set rolname ='root' where rolname = 'postgres';

But be aware, that munching the system catalogues by hand is always a little dangerous.