Design approach to decouple DB write to reduce application latency

Question

I want to use DynamoDB to save application operation data at the end of a session for auditing purposes without affecting the actual application latency. Because this date is only for auditing so we don't want to impact our prod latencies. I have few questions for implementing this:

1. Should I decouple the DB write activity with an SQS? So, the Db write delay will have no effect on the actual application?
2. is publishing messages in SQS have the same latency as writing data in DynamoDB then we don't need SQS?
3. what would be the best design technique for dealing with these scenarios?

Answer 1

Just create a separate thread for sending the auditing data to the database. That way the main thread which runs the actual application won't be slowed down by any database activity which happens on the second thread(s).

If you don't want any congestion on the database which originates from auditing data to interfere with the performance of regular data at all, then a more extreme measure would be to set up an entirely separate DynamoDB instance just for the auditing data. While this might be more expensive, there might also be compliance arguments for doing that.