A DynamoDB table uses a partition key with only a handful of distinct values (e.g., a status field), so a few keys receive most of the traffic and get throttled. What's the fix?
A.Switch to on-demand capacity mode
On-demand raises capacity ceilings but hot partitions still throttle within a partition.
B.Choose a high-cardinality partition key (e.g., user ID) that spreads requests evenly
Correct. Even distribution across partitions requires a high-cardinality partition key.
C.Add a global secondary index on status
A GSI on a low-cardinality attribute creates the same hot-partition problem in the index.
D.Enable DynamoDB Streams
Streams emit change events; they don't affect partitioning.
Why this answer
DynamoDB distributes data by partition key; low-cardinality keys concentrate load into 'hot' partitions. A high-cardinality key (or key suffixing/composite design) spreads requests across partitions — the fundamental DynamoDB performance principle.
Correct answer: B · Last reviewed 2026-10-25
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