What are two key customer responsibilities when using a database hosted on Amazon Elastic Compute Cloud (EC2)?

When utilizing a database hosted on Amazon Elastic Compute Cloud (EC2), it is essential for customers to take on certain responsibilities to ensure the smooth operation and performance of their database. One of these key responsibilities is application optimization. This involves tuning the database and its queries, ensuring that it operates efficiently, which can include indexing, query optimization, and managing the overall architecture of the application that interacts with the database.

Another critical responsibility is handling operating system patches. Since the EC2 instance is under the customer's control, it is up to them to manage the underlying operating system to maintain security, stability, and performance. This includes applying updates and patches that address security vulnerabilities, which is vital for keeping the database secure and functional.

The other options highlight responsibilities that, while important in their own right, do not specifically pertain to the database operation on EC2. For example, security group configuration and network management are more about infrastructure setup rather than ongoing database management. Similarly, data backup and user management, while crucial, fall under broader administrative tasks that some customers might outsource or use managed services to handle effectively, rather than being direct responsibilities linked specifically to running a database on EC2. Database schema design and monitoring are indeed critical aspects of database management, but they