Databases

Amazon DynamoDB Global Tables automatically replicate data across multiple AWS regions, giving applications single‑digit millisecond read and write latency no matter where users connect. RDS Multi‑AZ provides high availability within a single region but does not deliver cross‑region low‑latency access; S3 Cross‑Region Replication moves object copies, not database records; CloudFront caches static files and cannot serve transactional database workloads.

Amazon DynamoDB provides single‑digit millisecond latency for key‑value access, and the DynamoDB Accelerator (DAX) adds an in‑memory cache that reduces read latency to sub‑millisecond levels. RDS is a relational database with higher query overhead, Redshift is an analytics warehouse optimized for bulk scans, and Aurora, while fast, still cannot match the sub‑ms performance of DynamoDB + DAX.

Amazon DynamoDB provides single‑digit millisecond latency for key‑value access, and the DynamoDB Accelerator (DAX) adds an in‑memory cache that reduces read latency to sub‑millisecond levels. A diagram for this topic isn't available yet — the worked example below walks the same reasoning step by step.

• !Read each option carefully — distractors on Databases are designed to look plausible.
• !Re-check the exact wording of the question stem before committing to an answer.
• !Watch the qualifiers ("always", "only", "except") that flip a correct-looking option.

Answer each from memory — you'll see instantly whether you're right and why.

Run a focused 10-question mini-mock on Databases and see it stick.