What is the MOST operationally efficient solution that meets these requirements?
Set up an S3 event notification that targets an Amazon Simple Notification Service (Amazon SNS) topic. Create two subscriptions for the SNS topic. Use one subscription to send the email notification. Use the other subscription to invoke an AWS Lambda function that inserts the record into the database.
Set up an Amazon CloudWatch alarm that enters ALARM state whenever an object is created in the S3 bucket. Configure the alarm to invoke an AWS Lambda function that sends the email notification and inserts the record into the database.
Create an AWS Lambda function to send the email notification and insert the record into the database whenever a new object is detected in the S3 bucket. Invoke the function every minute with an Amazon EventBridge (Amazon CloudWatch Events) scheduled rule.
Set up two S3 event notifications. Target a separate AWS Lambda function with each notification. Configure one function to send the email notification. Configure the other function to insert the record into the database.
Explanations:
S3 event notifications to SNS are efficient. SNS can send an email and also trigger Lambda for database insertion, fulfilling both requirements in a highly scalable manner.
CloudWatch alarms are not designed to trigger on object creation in S3; they are better for monitoring system states and thresholds, not specific S3 events like object uploads.
Using a scheduled EventBridge rule is inefficient because it would invoke the Lambda function every minute regardless of S3 activity, which is unnecessary and costly.
While S3 event notifications can trigger Lambda, setting up two separate Lambda functions for email and database insertion creates unnecessary complexity and operational overhead.
I plan that the answer is:
Set up an S3 event notification that targets an Amazon Simple Notification Service (Amazon SNS) topic. Create two subscriptions for the SNS topic. Use one subscription to send the email notification. Use the other subscription to invoke an AWS Lambda function that inserts the record into the database.