With Oracle Linux 8 you just run – because the package comes with
# dnf install -y oracle-database-preinstall-21c
and then If you want optionally
# yum update -y
But for non-Oracle dialects like RHEL 8 or CentOS 8 you can download and bang the package in as follows – saves a lot of time
curl -o oracle-database-preinstall-21c-1.0-1.el8.x86_64.rpm https://yum.oracle.com/repo/OracleLinux/OL8/appstream/x86_64/getPackage/ oracle-database-preinstall-21c-1.0-1.el8.x86_64.rpm yum -y localinstall oracle-database-preinstall-21c-1.0-1.el8.x86_64.rpm