AWS Certified Developer Associate Practice Exam 2025 – The Complete All-in-One Guide for Success!

The correct answer emphasizes that a scan operation is not more efficient than a query operation in terms of performance.

In DynamoDB, the query operation is designed to find specific items based on primary key values, which makes it significantly more efficient than a scan operation. A query uses key expressions to directly target data, meaning it only retrieves the relevant items that match the specified criteria. This targeted approach results in lower latency and reduced resource consumption.

In contrast, a scan examines every item in a table to find those that meet the filter criteria. This means that the larger the dataset, the more time and resources the scan will require, making it less efficient for performance. Moreover, scans can impact the performance of the database if they are run frequently or if the dataset is large, as they consume read capacity units for the entire table.

While there are scenarios where specific conditions could theoretically make a scan more attractive (like when a user needs to retrieve all items regardless of keys), these situations do not improve the performance aspect in a general sense. Thus, the answer clearly illustrates the efficiency differences between the two operations in DynamoDB.