Correct answer - "Use TTL" : Time To Live (TTL) for DynamoDB allows you to define when items in a
table expire so that they can be automatically deleted from the database. TTL is provided at no
extra cost as a way to reduce storage usage and reduce the cost of storing irrelevant data
without using provisioned throughput. With TTL enabled on a table, you can set a timestamp for
deletion on a per-item basis, allowing you to limit storage usage to only those records that are
relevant.
Incorrect Answers -
"Use DynamoDB Streams" - These help you get a changelog of your DynamoDB table but won't help you
delete expired data. Note that data expired using a TTL will appear as an event in your DynamoDB
stream
"Use DAX" - This is a caching technology for your DynamoDB tables
"Use a Lambda function" - This could work but would require setting up indexes, queries or scans
in order to work, as well as trigger them often enough using a CloudWatch Events. That band-aid
solution would never be as good as using the TTL feature in DynamoDB