Exam AWS Certified Developer - Associate DVA-C02 topic 1 question 35 discussion

The correct answer is B. To insert a record into DynamoDB as soon as a new file is added to an S3 bucket, you can configure an S3 event notification to invoke an AWS Lambda function that inserts the records into DynamoDB. When a new file is added to the S3 bucket, the S3 event notification will trigger the Lambda function, which will insert the record into the DynamoDB table. Option A is incorrect because Amazon EventBridge is not necessary to achieve this. S3 event notifications can directly invoke a Lambda function to insert records into DynamoDB. Option C is incorrect because polling the S3 bucket periodically to check for new files is inefficient and not necessary with S3 event notifications. Option D is incorrect because running a cron job at a scheduled time is not real-time and would not insert the record into DynamoDB as soon as a new file is added to the S3 bucket.

B https://docs.aws.amazon.com/AmazonS3/latest/userguide/NotificationHowTo.html

A) Eliminated - This approach introduces unnecessary complexity when S3 already supports native event notifications to Lambda. B) Correct - S3 has native support for event notifications to trigger Lambda functions C) Eliminated - Polling is inefficient and unnecessary D) Eliminated - This is a time-based solution, not event-driven, meaning there could be a delay between the file being added and the record being inserted.

==> Discard A: EventBridge is unnecessary because S3 already provides direct event notifications. ==> Discard C: Polling violates the "as soon as" requirement due to delay and inefficiency. ==> Discard D: Cron jobs do not respond immediately, violating the "as soon as" requirement. B is correct because S3 event notifications can trigger a Lambda function immediately when a new file is added, ensuring real-time insertion into DynamoDB. B is better than A because S3 event notifications directly trigger a Lambda function, eliminating the need for additional configuration or services like EventBridge, making it simpler and more efficient.

B is the correct answer.

A is also a solution for this which is better if we want loose coupling but will introduce a slight latency. The key word here is "as soon as" so the correct answer will be B.

It is B