What benefit does the SNS and SQS Fan-out pattern provide?

The SNS and SQS Fan-out pattern is an architectural design that allows for the distribution of messages from a single source to multiple subscribers simultaneously. When Amazon Simple Notification Service (SNS) is integrated with Amazon Simple Queue Service (SQS), a message published to an SNS topic can be delivered to multiple SQS queues. Each queue can then be processed independently and concurrently by different consumer applications or services.

This parallel processing capability is a significant advantage as it enhances the overall throughput of message handling in a distributed system. By allowing multiple subscribers to consume the same message without waiting for each other to finish processing, the system can scale out more effectively, leading to a more efficient utilization of resources and quicker responses to events.

The other options do not accurately reflect the main benefit of the SNS and SQS Fan-out pattern. For example, processing messages in sequence does not leverage the fan-out capability, and automatic database scaling is unrelated to message distribution. Similarly, managing stateful transactions is a different concern outside the context of message brokering provided by SNS and SQS.