PostgreSQL : Restrict (another) superuser from accessing database

Postgres is a Superuser which override all access restrictions ，I thinks it's not possbile to restrict the superuser 'postgres' to access the database 'Movies'

francs is entirely correct. superuser means just that. They're all-powerful. They can do anything, including load additional code into the database, modify tables on disk directly, etc. See CREATE ROLE and the documentation on client authentication for more information.

If you don't trust them, don't give them superuser rights. In this case, it sounds like you should've just done a CREATE DATABASE movies WITH OWNER the_other_user and given them a normal, non-superuser login. Or if they need to create their own databases, you could give them CREATEDB rights.

The only way to restrict a superuser is by changing the C code inside PostgreSQL directly. Even then you'd probably be wasting your time, as a determined user could get around restrictions like a ProcessUtility_hook filter if they have superuser access.

Remove their superuser access. Unless they've had the foresight to backdoor your system in a way that'll let them regain access (unlikely, and not trivial) you should be OK.

ALTER USER the_user WITH NOSUPERUSER;

You can add CREATEDB rights if you want them to have the ability to create databases.

You have already been told that you cannot stop a superuser. You have to aim higher: create another database cluster using initdb (which will run on a separate port).

Users are valid cluster-wide. A superuser in one cluster has no "jurisdiction" in another cluster.

You can "reject" the postgres user for your specifique database using pg_hba.conf.

sample for the database no_postgres (you need to reload your server) :

local   no_postgres     postgres        reject
host    no_postgres     postgres        0.0.0.0 255.255.255.255 reject

And now :

postgres=# create database no_postgres;
CREATE DATABASE
postgres=# \c no_postgres 
FATAL:  pg_hba.conf rejects connection for host "[local]", user "postgres", database "no_postgres"
Previous connection kept
postgres=#