Logged in as postgres but getting the error createuser: creation of new role failed: ERROR: must be superuser to create superusers

Question

I need to create a superuser so I can create a db, but I'm having trouble with this. I'm logged in as the user postgres:

sudo su - postgres

But when I try to create a superuser, I get the following problem:

$createuser glassboard;
Shall the new role be a superuser? (y/n) y

createuser: creation of new role failed: ERROR: must be superuser to create superusers

This also happens if I try to create a new user in psql and then make him a superuser:

$ psql -U postgres
psql (9.1.4)
Type "help" for help.

postgres=> create user glassboard
postgres-> ;
ERROR:  permission denied to create role

How do I create a superuser?

output of \\du in postgres:

postgres=> \du

                             List of roles
 Role name |                   Attributes                   | Member of 
-----------+------------------------------------------------+-----------
 main      | Superuser, Create role, Create DB, Replication | {}
 postgres  |                                                | {}

Answer 1

Some OSX packages don't create a postgres superuser database account. The superuser is named differently, in your case it's main .

When you do psql -U main without specifying a database, it defaults to the same name as the user. If you don't have a database named main , indicate a different database with the -d option.

If you have no database to connect to, use template1

psql -U main -d template1

If still you want to grant superuser to postgres , do once logged inside psql:

alter user postgres superuser;

Answer 2

In my case on PostgreSQL 9.2, the postgres superuser was created, but when I went to create additional superusers from the postgres user, I was never prompted with Shall the new role be a superuser? (y/n) Shall the new role be a superuser? (y/n) so the new user was created with default permissions. To fix this, I just ran this command as the postgres user: ALTER USER myuser WITH SUPERUSER;

Answer 3

On Mac OS default installation

The default superuser is not postgres , but the current mac-os user. In order to solve that:

1 . Connect to your DB with your current (system) user. The below example connects to DB named "postgres":

psql -d postgres

you should get into psql prompt, like postgres=#

2 . Grant superuser to well-known postgres username:

ALTER ROLE postgres superuser;

If everything went smoothly, you'll see the response: ALTER ROLE

3 . Enjoy! ( \\q to quit)

Answer 4

我在 macOS Sierra (10.12.2) 上使用 PostgreSQL 9.6（不是说我的解决方案不适用于旧版本或新版本），真正对我有用的是使用以下命令行创建另一个用户：

createuser -s anotheruser

Answer 5

Had the same issue about not being able to create a new user, after creating a database and logging into that database as the superuser.

This is what worked for me (unfortunately I didn't have time to study the why), on Debian 10, Postgresql12

Log into the system default db (postgres) as the default superuser (in my case I had just installed it, so).

psql -d postgres

and then I was able to create the user, with exactly the same command line that didn't work when I was logged under the database I had created: create user xxxx with password 'yyyyyy';

Then I granted all on the new database that I had created

grant all on database newly_created_database to xxxx;