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

The correct answer is D because Amazon Redshift row-level security provides granular access control over sensitive records by applying security policies at the database object level. This directly supports the requirement to let researchers access only records from their own departments without creating multiple copies of the dataset. Multi-condition SQL predicates are stronger than basic department-only filters because they can include department, role, sensitivity, and authorization logic in the same policy design. Creating separate schemas and views increases administrative overhead and can become inconsistent. Datashares are useful for sharing data but the option creates unnecessary departmental copies and does not solve record-level restriction by itself. Granting EXPLAIN RLS to researchers is also not needed for normal secure access.

 Using an S3 bucket that is in the same AWS Region where the company runs Athena queries can improve query performance by reducing data transfer latency and costs. Preprocessing the .csv data to Apache Parquet format can also improve query performance by enabling columnar storage, compression, and partitioning, which can reduce the amount of data scanned and fetched by the query. These solutions can optimize the storage solution for the POC test without requiring much effort or changes to the existing data pipeline. The other solutions are not optimal or relevant for this requirement. Adding a randomized string to the beginning of the keys in Amazon S3 can improve the throughput across partitions, but it can also make the data harder to query and manage. Using an S3 bucket that is in the same account that uses Athena to query the data does not have any significant impact on query performance, as long as the proper permissions are granted. Preprocessing the .csv data to JSON format does not offer any benefits over the .csv format, as both are row-based and verbose formats that require more data scanning and fetching than columnar formats like Parquet. References:

Best Practices When Using Athena with AWS Glue

Optimizing Amazon S3 Performance

AWS Certified Data Engineer - Associate DEA-C01 Complete Study Guide

The company wants to use Amazon Kinesis Data Firehose to transform CSV files into JSON format and store the files in Apache Parquet format with the least development effort.

Option B: Use Kinesis Data Firehose to convert the CSV files to JSON and to store the files in Parquet format.Kinesis Data Firehose supports data format conversion natively, including converting incoming CSV data to JSON format and storing the resulting files in Parquet format in Amazon S3. This solution requires the least development effort because it uses built-in transformation features of Kinesis Data Firehose.

Other options (A, C, D) involve invoking AWS Lambda functions, which would introduce additional complexity and development effort compared to Kinesis Data Firehose’s native format conversion capabilities.