Answer: Create a read replica. Move reporting queries to the read replica.

## Explanation **Correct Answer: A** **Why Option A is correct:** 1. **Read replicas** in Amazon RDS allow you to offload read traffic from the primary database instance. 2. By moving reporting queries (which are read-only) to a read replica, you separate the read workload from the write workload. 3. This prevents the long-running reporting queries from interfering with the order processing (write operations) on the primary instance. 4. Employees can still perform their reporting queries during business hours without causing timeouts in the ordering application. 5. This solution maintains the existing architecture while solving the performance issue. **Why Option B is incorrect:** - Distributing the ordering application between primary and read replica is not appropriate because: - Read replicas have asynchronous replication, which means there might be replication lag - Ordering applications typically require strong consistency for write operations - Splitting the application could lead to data consistency issues **Why Option C is incorrect:** - Migrating to DynamoDB is a major architectural change that: - Would require significant application rework - Might not be suitable for relational data structures - Doesn't address the immediate problem of separating read and write workloads - Is an over-engineered solution for this specific issue **Why Option D is incorrect:** - Scheduling queries for non-peak hours: - Doesn't meet the requirement that employees need to perform queries during business hours - Limits business flexibility - Doesn't solve the underlying architectural issue of mixed read/write workloads **Key AWS Concepts:** - **Amazon RDS Read Replicas**: Provide read scalability by creating copies of your primary database that can serve read traffic - **Read/Write Separation**: A common pattern where read-heavy workloads are directed to read replicas while write operations go to the primary instance - **Performance Isolation**: Separating different types of workloads to prevent interference **Best Practice:** Using read replicas for reporting and analytics workloads is a standard AWS best practice to maintain application performance while supporting business intelligence needs.

Author: LeetQuiz Editorial Team