Amazon Web Services Data-Engineer-Associate Exam With Confidence Using Practice Dumps

Option C is correct because the fastest design combines a columnar storage format with partitioning on the most common query predicate. AWS Athena guidance says that Parquet and ORC are optimized columnar formats and that columns frequently used as filters are good candidates for partitioning. AWS also states that when a query filters on a partition key, the engine reads only matching partitions, which significantly reduces data scanned. Since the company’s main analytical need is insights specific to sensor categories, partitioning by sensor category provides the strongest pruning. Sorting by date then helps organize time-based data within each category partition.

Options B and D use CSV, which is row-based and much slower for analytical scans than Parquet or ORC. Option A uses a good format, but partitioning by date is less optimal than partitioning by sensor category when category is the main filter in the company’s queries. The study guide also identifies Parquet as the preferred analytic storage format for efficient columnar queries.

Option B is correct because the requirement is to retain a very large dataset indefinitely and analyze it from Amazon Redshift in the most cost-effective way. Amazon Redshift Spectrum allows Redshift to query data directly in Amazon S3 without loading all of the data into Redshift-managed storage. That reduces warehouse storage cost for long-term retained data. AWS documentation also recommends using Apache Parquet for Spectrum because Parquet is a columnar format, which allows Redshift Spectrum to read only the columns needed instead of scanning entire text files. This improves performance and lowers query cost.

Option A and D are less cost-effective because auto-copy loads data into the Redshift cluster, which means the company pays to store all historical data in Redshift even though the requirement is indefinite retention of a large volume of IoT data. Option C is worse than B because JSON is a row-oriented text format, and AWS guidance says columnar formats such as Parquet or ORC are preferred for Redshift Spectrum for better scan efficiency and lower cost.

Option A is the most direct and operationally efficient way to trigger the existing Lambda-based load into Amazon Redshift whenever a new CSV file is uploaded to Amazon S3. The key requirement is event-driven automation on “new object created” events, and the study material explicitly describes using Amazon EventBridge to react to S3 uploads by creating a rule on the default event bus and routing matching events to a target application.

Compared with queue-based designs (Options B and D), Option A reduces components: there is no need to manage an SQS queue, batching/visibility timeout behavior, or retry semantics at the consumer layer. This is especially appropriate because the files are small (≤ 5 MB) and the Lambda function is already implemented to perform the copy/load step. Using DMS (Option C) is not designed for “S3 object arrival → Lambda → Redshift” event triggering; it introduces unnecessary services and operational work for a simple file-ingestion trigger.

Therefore, integrating S3 event notifications with EventBridge and targeting the Lambda function best meets the requirement with the least added complexity.