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

Option A is correct because Amazon Redshift dynamic data masking is designed to hide, obfuscate, or partially reveal sensitive values at query time without duplicating the underlying data. AWS states that masking policies can be attached to one or more columns and can be applied differently to certain users or roles. AWS also provides examples where different roles see different versions of the same column value, which matches the requirement that customer support users see only the last four characters while audit users can see the full value.

Option B is incorrect because metadata security controls metadata visibility, not column-value masking. Option C is incorrect because row-level security filters which rows are visible; it does not selectively mask part of a column value. Option D would create a second table and therefore duplicates data, which the question forbids. Dynamic data masking is the AWS-native feature that satisfies role-based partial exposure of a single sensitive column with no data duplication.

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.

A “No space left on device” error typically results from data skew or large shuffle stages. The best actions are:

B. Monitor using Spark UI and Glue metrics to find skewed partitions or executor issues.

D. Use --write-shuffle-files-to-s3 to offload intermediate data to S3 instead of local disk, and apply salting to reduce skew.

“You can reduce the impact of data skew and large shuffle operations by monitoring with Spark UI and enabling the --write-shuffle-files-to-s3 option. Salting can help rebalance the skewed keys.”

– Ace the AWS Certified Data Engineer - Associate Certification - version 2 - apple.pdf

Scaling out workers (A, C) is more costly and less efficient if the root cause (skew) is not fixed.