How to install and setup PostgreSQL on RHEL 8

To install and set up PostgreSQL on Red Hat Enterprise Linux (RHEL) 8, follow these steps:

1. Enable the PostgreSQL module repository by running the following command:

dnf module enable postgresql:12

2. Install the PostgreSQL server package using the following command:

dnf install postgresql-server

3. Initialize the PostgreSQL database using the following command:

/usr/pgsql-12/bin/postgresql-12-setup initdb

4. Start the PostgreSQL service and enable it to start at boot time using the following commands:

systemctl start postgresql-12
systemctl enable postgresql-12

5. By default, PostgreSQL listens on a Unix socket located at /var/run/postgresql. To access the database from a remote machine, you will need to configure PostgreSQL to listen on a network interface. To do this, edit the /var/lib/pgsql/12/data/postgresql.conf file and set the listen_addresses parameter to '*'.

6. You will also need to configure PostgreSQL to accept connections from remote clients. To do this, edit the /var/lib/pgsql/12/data/pg_hba.conf file and add the following line:

host    all             all             0.0.0.0/0               md5

This will allow any client to connect to the database using a password.

7. Restart the PostgreSQL service to apply the changes:

systemctl restart postgresql-12

8. To create a new PostgreSQL user and database, connect to the database using the psql command-line client:

sudo -u postgres psql

Then, use the CREATE USER and CREATE DATABASE commands to create the user and database, respectively:

CREATE USER username WITH PASSWORD 'password';
CREATE DATABASE database_name WITH OWNER username;