Here is the only reference to Oracle I can find in the install docs.
As mentioned you will need the Oracle client software installed in your Viya 4 environment.
This Communities post explains in more detail how to configure Viya 4 data connectors.
It would be worth opening a Tech Support Track to work through the steps you are unsure about. Viya 4 is still pretty new and there aren't a lot of Community users with the firsthand experience to help. Also Viya 4 seems to be using more of a cloud-based SaaS delivery model which doesn't help those who prefer a more DIY approach 😉
Feel free to post additional details back in this post. I'm interested as Viya 4 is on our radar along with many others.
Generally speaking, you need the client to be on a file system we can mount into any pods that need it. Often this is done using the NFS server deployed by the IAC. You create a path for the Oracle client within the NFS share, extract the oracle client there, and then use the sample data-access YAML files to mount the NFS to the pods as needed. Then you define the environment variables with the sas-access.properties file to point to the mounted path. The README.md file in $deploy/sas-bases/examples/data-access has more detail on this, or $deploy/sas-bases/docs/configuring_sasaccess_and_data_connectors_for_sas_viya_4.htm if you'd like to view it with a browser.
Here's a link to the HTML doc from the latest stable release:
The SAS Users Group for Administrators (SUGA) is open to all SAS administrators and architects who install, update, manage or maintain a SAS deployment.
Learn how to install the SAS Viya CLI and a few commands you may find useful in this video by SAS’ Darrell Barton.
Find more tutorials on the SAS Users YouTube channel.