Ingesting Oracle to S3 Parquet with Least Effort

DEA-C01 By islever Editorial Last updated

Perform data ingestion.

Short answer

C Create an AWS DMS task for ongoing replication to S3 in Parquet format.

Question

A company is building a data lake for a new analytics team. The company is using Amazon S3 for storage and Amazon Athena for query analysis. All data that is in Amazon S3 is in Apache Parquet format. The company is running a new Oracle database as a source system in the company’s data center. The company has 70 tables in the Oracle database. All the tables have primary keys. Data can occasionally change in the source system. The company wants to ingest the tables every day into the data lake. Which solution will meet this requirement with the LEAST effort?
  1. Create an Apache Sqoop job in Amazon EMR to read the data from the Oracle database. Configure the Sqoop job to write the data to Amazon S3 in Parquet format.
  2. Create an AWS Glue connection to the Oracle database. Create an AWS Glue bookmark job to ingest the data incrementally and to write the data to Amazon S3 in Parquet format.
  3. Create an AWS Database Migration Service (AWS DMS) task for ongoing replication. Set the Oracle database as the source. Set Amazon S3 as the target. Configure the task to write the data in Parquet format. Correct Answer
  4. Create an Oracle database in Amazon RDS. Use AWS Database Migration Service (AWS DMS) to migrate the on-premises Oracle database to Amazon RDS. Configure triggers on the tables to invoke AWS Lambda functions to write changed records to Amazon S3 in Parquet format.

Key Takeaways

Tests knowledge of AWS DMS capabilities as a managed replication tool versus self-managed solutions like Sqoop or Glue bookmarks.

Determines the optimal AWS service for migrating on-premises Oracle data to Amazon S3 in Parquet format with minimal configuration effort.

Common mistake: Candidates often select AWS Glue (B) assuming bookmarks handle incremental loads, but Glue is primarily for ETL processing, not direct database-to-S3 replication with automatic schema discovery and Parquet conversion out-of-the-box.

Expert Analysis

Why the Answer Is Correct

AWS Database Migration Service (DMS) is designed specifically for continuous data replication from source databases to various targets, including Amazon S3. It supports full load and ongoing replication, automatically handles schema mapping, and can write data directly to S3 in Apache Parquet format without requiring custom code or complex job orchestration. This meets the requirement of ingesting tables daily with the least amount of development and maintenance effort.

Why the Other Options Are Wrong

Option A requires building and maintaining an EMR cluster and writing/maintaining Sqoop scripts, which is high effort. Option B uses AWS Glue; while it can connect to Oracle, 'bookmarks' are used to track processed files during re-runs, not to detect changes in the source database itself. Implementing incremental ingestion via Glue would require custom logic or additional services. Option D involves migrating the DB to RDS first, then using triggers and Lambda, which adds significant complexity and latency compared to a direct DMS task.

Community Comment Notes

The community strongly favored option C, with 90% of votes selecting it. One user noted that DMS allows S3 as a target with Parquet formatting configured directly. Another user dismissed Glue bookmarks as being for file tracking rather than source change detection. The consensus confirms that DMS is the standard managed solution for this scenario.

Official Reference

https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Target.S3.html

This link opens the official vendor documentation in a new tab.

Exam Strategy

When asked for 'least effort' in data migration scenarios, prioritize fully managed services like AWS DMS over self-managed tools like Sqoop or EMR, especially when the target is S3.

Frequently Asked Questions

Why is AWS Glue bookmark incorrect for incremental ingestion?

Bookmarks track processed files to avoid duplicates on re-run, they do not detect changes in the source database like primary key updates.

Can AWS DMS write directly to S3 in Parquet?

Yes, DMS supports S3 as a target and can serialize data into Parquet format automatically.

More DEA-C01 FAQ →

Community Votes

C
100%

100% of anonymous learners picked answer C. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 3 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 3

  1. dashapetr 👍 8 Answered C
    C: You can use S3 as a target and configure files to be in Parquet format https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Target.S3.html
  2. michele_scar 👍 1 Answered C
    A and D wrong. B also wrong because Bookmark is used to mantain files that you don't want to re-analyze in case of a re-run about a glue job.
  3. siheom 👍 1 Answered B
    VOTE B

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