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

Option C is correct because the company only needs to keep the original files for 90 days and then delete them. AWS states that S3 Lifecycle can be used to delete expired objects automatically, which directly matches this requirement. There is no need to transition the objects to another storage class because the files are not needed beyond day 90. Adding a transition step would add complexity and, in this case, would not improve cost-effectiveness.

Option A is not optimal because S3 Glacier Flexible Retrieval has a 90-day minimum storage duration and is intended for longer-term archival. Transitioning objects right before deleting them is unnecessary overhead and can add minimum-duration charges. Option B is incorrect because Object Lock is for retention and write-once-read-many protection, not for normal temporary retention with lowest cost. Option D is also less cost-effective because S3 Intelligent-Tiering is useful when access patterns are uncertain, but here the retention period and deletion timing are already known. The simplest and cheapest solution is to keep the originals in S3 Standard for the required 90 days and then expire them with Lifecycle.

When AWS Glue jobs run inside a private subnet, they must use secure and supported methods to access external databases. AWS Glue supports JDBC connections to on-premises databases, but best practices require secure credential management and explicit driver configuration.

Using a JDBC driver stored in Amazon S3 allows Glue to connect to PostgreSQL without relying on default drivers. Storing credentials in AWS Secrets Manager eliminates hard-coded credentials and enables secure rotation, aligning with AWS security best practices.

Simply specifying credentials inline is less secure and not recommended. SASL connections are not supported for PostgreSQL JDBC connections. Security groups alone do not establish connectivity or authentication.

Therefore, Option D is the correct and production-grade solution.

Amazon S3 Intelligent-Tiering is designed to optimize storage costs by automatically moving objects between access tiers based on access patterns. Since Apache Iceberg works with S3 storage, using Intelligent-Tiering provides cost-efficiency without the need for custom development or jobs.

Option B improves performance but doesn ' t optimize cost automatically.

Option C is not a real AWS Glue feature – Glue does not automatically optimize Iceberg storage.

Option D requires custom development effort, which is contrary to the requirement.

“S3 Intelligent-Tiering is ideal for data lakes and analytics use cases that access data irregularly.”