Whenever a new order item is written to a DynamoDB table, a Lambda function must update a search index. What mechanism delivers the item-change events?
A.A scheduled Lambda that scans the table every minute
Polling scans are inefficient and miss sub-minute granularity.
B.DynamoDB Streams triggering the Lambda function
Correct. Streams → Lambda is the native CDC integration.
C.An SNS topic on the table
DynamoDB doesn't emit item events to SNS natively.
D.CloudTrail events on the table
CloudTrail records control-plane API calls, not item writes.
Why this answer
DynamoDB Streams captures item-level changes (inserts/updates/deletes) in near-real-time and integrates directly with Lambda via event source mapping — ordered per primary key, retained 24h. The designed answer for change-driven processing.
Correct answer: B · Last reviewed 2026-10-28
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