What is required for Data Guard implementation in OCI DB Systems?

For Data Guard implementation in Oracle Cloud Infrastructure (OCI) Database Systems, both database systems must reside within the same Virtual Cloud Network (VCN). This requirement is crucial because Data Guard relies on network connectivity between the primary and standby database systems to ensure that data is replicated, and any changes made in the primary database are quickly transferred to the standby instance.

Being in the same VCN allows for low-latency communication and facilitates the configuration of secure network settings that are essential for Data Guard functionality. This setup also simplifies the overall network architecture and enables easy management of networking resources such as security lists or network security groups, which control traffic flow to and from the database systems.

While other options may present various aspects of Database Systems and Data Guard configurations, they do not correctly align with the technical requirements for a successful Data Guard setup. For instance, Data Guard can be configured for both VM and bare metal DB systems (contrary to the first option), there is no requirement related to compartments (contrary to the second option), and port 1521 must indeed be open for database communication (contrary to the fourth option). Therefore, the necessity for both DB systems to be within the same VCN is a key aspect of Data Guard implementation in OCI.