Step-by-Step Guide

1. Update the Package Index
   Open a terminal and update the package index to ensure you have the latest information about available packages:

   sudo yum update -y

2. Add the PostgreSQL Repository
   Install the PostgreSQL repository RPM:

   sudo yum install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm

3. Disable the Built-in PostgreSQL Module
   Disable the built-in PostgreSQL module to avoid conflicts:

   sudo yum -qy module disable postgresql

4. Install PostgreSQL
   Install PostgreSQL using the yum package manager. Replace XX with your desired PostgreSQL version (e.g., 13 for PostgreSQL 13):

   sudo yum install -y postgresqlXX-server

5. Initialize the Database
   Initialize the PostgreSQL database:

   sudo /usr/pgsql-XX/bin/postgresql-XX-setup initdb

6. Start and Enable PostgreSQL
   Start the PostgreSQL service:

   sudo systemctl start postgresql-XX

Enable PostgreSQL to start on boot:

   sudo systemctl enable postgresql-XX

7. Verify PostgreSQL Installation
   Check the PostgreSQL service status to ensure it is running:

   sudo systemctl status postgresql-XX

If PostgreSQL is running, you should see an active (running) status.

8. Log In to PostgreSQL
   Switch to the postgres user and access the PostgreSQL prompt:

   sudo su - postgres
   psql

9. Set Up a New PostgreSQL Role
   To create a new PostgreSQL role, use the following SQL command within the PostgreSQL prompt:

   CREATE USER your_username WITH PASSWORD 'your_password';

10. Create a New Database
    To create a new database owned by the new user, use the following SQL command: CREATE DATABASE your_database_name OWNER your_username;
11. Grant Privileges (Optional)
    To grant all privileges on the database to the new user, use the following SQL command: GRANT ALL PRIVILEGES ON DATABASE your_database_name TO your_username;
12. Exit PostgreSQL Prompt
    Exit the PostgreSQL prompt by typing: \q
13. Test PostgreSQL Connection
    To test the connection, switch back to your regular user account and try connecting to the new database: psql -U your_username -d your_database_name You will be prompted to enter the password for the new user. Once logged in, you can list the tables to ensure the connection is successful: \dt
14. Backup and Restore Databases (Optional)
    To back up a PostgreSQL database, use the pg_dump command:
    bash pg_dump -U your_username your_database_name > your_database_name.sql
    To restore a database from a backup file, use the psql command:
    bash psql -U your_username -d your_database_name < your_database_name.sql