A DynamoDB-backed catalog suffers hot-key read spikes on popular items during flash sales, pushing reads from ~5ms to higher latency. What reduces read latency and offloads repeated reads MOST effectively?
A.Enable DynamoDB Auto Scaling
Auto Scaling prevents throttling on capacity but does not create a microsecond read path.
B.Add DynamoDB Accelerator (DAX), an in-memory cache, for read-heavy access
Correct. DAX caches item/query results in memory for repeated hot reads.
C.Convert the table to provisioned capacity
Capacity mode affects billing/limits, not latency for repeated identical reads.
D.Enable DynamoDB Streams
Streams capture changes for processing; they do not accelerate reads.
Why this answer
DAX is a fully managed in-memory cache for DynamoDB that serves repeated reads in microseconds, smoothing hot-key spikes. Auto Scaling adjusts capacity but does not cut per-read latency for identical hot keys.
Correct answer: B · Last reviewed 2026-10-25
Official AWS references
Practice this interactively
Answer without seeing the solution first in the Database Selection & Scaling practice session.
Practice Database Selection & Scaling