Oracle RAC One Node is available with Oracle Database Appliance
Oracle Real Application Clusters One Node (Oracle RAC One Node) is a single instance of an Oracle RAC database that runs on one node in a cluster. Instead of stopping and starting instances, you can use the Oracle RAC One Node online database relocation feature to relocate an Oracle RAC One Node instance to another server.
Administration of Oracle RAC One Node databases on Oracle Database Appliance is different from administering Oracle RAC or single-instance Oracle Databases. For Oracle RAC One Node databases, one node is the primary node, and the other node is a candidate node, which is available to accommodate services if the primary node fails, or is shut down for maintenance. The nodes, Oracle Databases, and database services reside in the generic server pool.