Which service allows users to deploy Oracle Database systems in OCI?

The Oracle Database Cloud Service is specifically designed for deploying Oracle Database systems within Oracle Cloud Infrastructure (OCI). This service provides users with the capabilities to easily provision and manage database environments, enabling them to take advantage of Oracle's robust database technology in a cloud-native manner. With the Database Cloud Service, users can create and configure database instances, scale their databases as needed, and manage backups and security settings efficiently.

In contrast, the other options do not focus on database deployment. Oracle Cloud SQL Service is more targeted towards SQL capabilities and may not offer the full range of database functionalities as the Database Cloud Service. Oracle Cloud Storage Service is focused on data storage, providing services for file storage and object storage, but does not directly relate to database deployment. Finally, Oracle Compute Cloud Service offers virtual machines for running various workloads but does not provide the specific features and optimizations necessary for deploying Oracle Database systems. Thus, the Oracle Database Cloud Service is the correct answer for deploying Oracle Database systems in OCI.