1. Add the PostgreSQL repository

[root@localhost software]# dnf install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-9-x86_64/pgdg-redhat-repo-latest.noarch.rpm

2. Disable your system’s built-in PostgreSQL module to avoid installing the wrong version

[root@localhost software]# dnf -qy module disable postgresql

3. Install the PostgreSQL server by running this command.
    If you want to set up another version, replace 17 with the corresponding number:

[root@localhost software]# dnf install -y postgresql17-server

4. initialize the database and enable automatic start

[root@localhost software]# /usr/pgsql-17/bin/postgresql-17-setup initdb
Initializing database ... OK

[root@localhost software]# systemctl list-unit-files --type=service | grep postgre
postgresql-17.service                      disabled        disabled

[root@localhost software]# systemctl enable postgresql-17
Created symlink /etc/systemd/system/multi-user.target.wants/postgresql-17.service → /usr/lib/systemd/system/postgresql-17.service.

[root@localhost software]# systemctl start postgresql-17
[root@localhost software]# systemctl status postgresql-17

5. Connect to the PostgreSQL shell and Change postgres's password

[root@localhost software]# su - postgres
[postgres@centos9 ~]$ psql
psql (17.4)
Type "help" for help.

postgres=# \l
                                                     List of databases
   Name    |  Owner   | Encoding | Locale Provider |   Collate   |    Ctype    | Locale | ICU Rules |   Acces
s privileges   
-----------+----------+----------+-----------------+-------------+-------------+--------+-----------+--------
---------------
 postgres  | postgres | UTF8     | libc            | en_US.UTF-8 | en_US.UTF-8 |        |           | 
 template0 | postgres | UTF8     | libc            | en_US.UTF-8 | en_US.UTF-8 |        |           | =c/post
gres          +
           |          |          |                 |             |             |        |           | postgre
s=CTc/postgres
 template1 | postgres | UTF8     | libc            | en_US.UTF-8 | en_US.UTF-8 |        |           | =c/post
gres          +
           |          |          |                 |             |             |        |           | postgre
s=CTc/postgres
(3 rows)

postgres=# alter user postgres with password '**********';
ALTER ROLE
postgres=#