https://docs.cloud.oracle.com/en-us/iaas/Content/Database/Tasks/migrating.htm Migration Connectivity Options You have several connectivity options when migrating your on-premises databases to the Oracle Cloud Infrastructure. The options are listed below in order of preference.
FastConnect: Provides a secure connection between your existing network and your virtual cloud network (VCN) over a private physical network instead of the internet. For more information, see FastConnect.
IPSec VPN: Provides a secure connection between a dynamic routing gateway (DRG) and customer-premise equipment (CPE), consisting of multiple IPSec tunnels. The IPSec connection is one of the components forming a site-to-site VPN between a VCN and your on-premises network. For more information, see VPN Connect.
Internet gateway: Provides a path for network traffic between your VCN and the internet. For more information, see Internet Gateway.

https://docs.cloud.oracle.com/en-us/iaas/Content/Database/Concepts/overview.htm Bare Metal DB Systems Bare metal DB systems consist of a single bare metal server running Oracle Linux 6.8, with locally attached NVMe storage. If the node fails, you can simply launch another system and restore the databases from current backups.
When you launch a bare metal DB system, you select a single Oracle Database edition that applies to all the databases on that DB system. The selected edition cannot be changed. Each DB system can have multiple database homes, which can be different versions. Each database home can have only one database, which is the same version as the database home.