Free AWS DVA-C01 Actual Exam Questions - Question 6 Discussion
are made to items in an Amazon DynamoDB table. The function has been created, and appropriate
permissions have been added to the Lambda execution role. Amazon DynamoDB streams have been
enabled for the table, but the function is still not being triggered.
Which option would enable DynamoDB table updates to trigger the Lambda function?
It’s B, because without event source mapping, Lambda won’t listen to the stream events.
A. Changing StreamViewType to NEW_AND_OLD_IMAGES won’t trigger Lambda by itself; it just changes the data in the stream. The key missing step is connecting Lambda to the stream, which is what event source mapping does.
It’s definitely B. Enabling streams just activates the data capture, but without an event source mapping, Lambda won’t know to pull events from the stream. Options A and D don’t directly affect triggering; A just changes data details and D is unrelated to invocation. SNS isn’t involved in this flow, so C can be ruled out. The key is linking the stream to Lambda using event source mapping so updates actually fire the function.
B/C? I know DynamoDB streams alone don’t automatically trigger Lambda—it needs that event source mapping (B). SNS mapping (C) doesn’t usually connect directly with streams, so B makes more sense here.
Isn’t enabling DynamoDB streams already enough? Wondering if the missing step is setting up the event source mapping between the stream and Lambda. Does anyone know if that’s mandatory here?