A multiplayer game keeps short-lived player session records keyed by a session identifier. The records are small, traffic varies by time of day, and the service must answer reads and writes in single-digit milliseconds as the player base grows. Which data store fits best?
Show answer and explanation
Answer: A
DynamoDB is a managed key-value and document store that returns single-digit millisecond responses and adds throughput without a cluster to size or patch. A session identifier maps directly to a partition key, and TTL can expire stale sessions without a cleanup job. The table scales horizontally, which suits player counts that change through the day.
Why the other options are wrong
- B. A relational engine would need instance sizing, connection management and index tuning for a workload that is a simple primary-key lookup.
- C. DocumentDB targets MongoDB-style documents and queries. Session records do not need document modelling, and the service is heavier than this workload requires.
- D. Timestream is built for timestamped measurements and time-window analytics, not for point lookups of current session state.
Exam tip. Simple key-value access at any scale with single-digit millisecond latency points to DynamoDB.