Your development team is currently planning on moving an on-premise data store to AWS DynamoDB. There were triggers defined in the prior database which was used for updates to existing items. How can you achieve the same when the movement is made to DynamoDB in the easiest way possible?

Answer options:

A.Define triggers in DynamoDB for each table.
B.Define Lambda functions in response to events from DynamoDB Streams.
C.Define SNS topics in response to events from DynamoDB Streams.
D.Define SQS topics in response to events from DynamoDB Streams.

Answer – B
The AWS Documentation mentions the following.
Amazon DynamoDB is integrated with AWS Lambda so that you can create triggers—pieces of code that automatically respond to events in DynamoDB Streams. With triggers, you can build applications that react to data modifications in DynamoDB tables.
If you enable DynamoDB Streams on a table, you can associate the stream ARN with a Lambda function that you write. Immediately after an item in the table is modified, a new record appears in the table`s stream. AWS Lambda polls the stream and invokes your Lambda function synchronously when it detects new stream records.
Option A is invalid since triggers cannot be defined by default in DynamoDB.Options C and D are invalid since the streams need to be integrated with Lambda.
For more information on using streams with AWS Lambda, please refer to the below URL-
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Streams.Lambda.html