a) Edit Configuration File
Open the /var/lib/pgsql/data/postgresql.conf file in your favorite text editor with superuser privileges. Find and uncomment the following line.# Port = 5432
Change the value to your desired port number. Suppose it will be 1702.Port = 1702
b) Let FirewallD Know
If you want remote access, you have to add the new port to FirewallD‘s allow list.sudo firewall-cmd --permanent --add-port=1702/tcp
You should remove the default, i.e., the previous port of PostgreSQL, from FirewallD‘s allow list.sudo firewall-cmd --permanent --remove-port=5432/tcp
Then reload FirewallD.sudo firewall-cmd --reload
c) Restart PostgreSQL
Restart the database server to make the change take effect.sudo systemctl restart postgresql.service