According to the "Tested Integrations" section of Red Hat Single Sign-On Supported Configurations, the following databases and database drivers were tested:

• MariaDB
• MySQL
• Oracle DB
• Microsoft SQL Server
• Enterprise DB Postgres Plus Advanced Server
• PostgreSQL
   
  The same document also states that RH-SSO has been tested with OpenShift of versions 3.11.117 and 4.9 and 4.10, but the RHSSO operator only supports the configuration of PostgreSQL DB connectivity.
   
  The Support for the unmanaged databases should be added to the RHSSO operator to address customer requirements. Our priorities, from top to bottom, are the following: * MariaDB/MySQL
• Microsoft SQL Server
• Oracle DB

As reference we will be linking the article cited above: 
https://access.redhat.com/articles/2342861#Cert_7_5
 
Please note that this request is coming from a partner engagement