DEA-C01 Data Store Management Practice Question
A data engineer is designing a data lake on Amazon S3. The data is ingested from multiple sources and needs to be partitioned by year, month, day, and event type for efficient querying with Amazon Athena. Which S3 key prefix structure is most appropriate?
⚠ Common exam trap
AWS often tests the distinction between Hive-style partitioning (key=value) and flat or date-only prefixes, where candidates mistakenly choose a structure that does not support partition pruning or is incompatible with Athena's partition discovery.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
s3://bucket/event_type=events/year=2024/month=01/day=01/data.parquet
Uses Hive-style partitioning (event_type=events/year=2024/month=01/day=01), which Athena and other query engines natively support. This structure allows Athena to perform partition pruning, reading only the relevant directories based on WHERE clause filters, significantly reducing data scanned and improving query performance. Option D also uses Hive-style partitioning but with a different order of partition keys (day, month, year). While still valid, this non-standard order may cause issues with automatic partition discovery when using MSCK REPAIR TABLE, which expects the partition order to match the table definition. Therefore, option C is the most appropriate because it follows the common convention of listing partitions from coarse to fine granularity (year > month > day) and can be easily loaded into Athena without additional configuration.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
s3://bucket/events/2024-01-01/event_type=data.parquet
Why it's wrong here
Flat date prefix without partition keys; Athena cannot prune partitions effectively.
- ✗
s3://bucket/2024/01/01/event_type/events/data.parquet
Why it's wrong here
Directory structure mimicking file system but missing partition key-value pairs; Athena requires Hive-style for partition discovery.
- ✓
s3://bucket/event_type=events/year=2024/month=01/day=01/data.parquet
Why this is correct
Correct Hive-style partitioning with logical key order (year, month, day) and event type, enabling efficient partition pruning.
- ✗
s3://bucket/day=01/month=01/year=2024/event_type=events/data.parquet
Why it's wrong here
Uses Hive-style partitioning but with an unconventional key order (day, month, year, event_type). While Athena can still read this structure with proper table definitions, the non-standard order may complicate automatic partition discovery and is not the most appropriate choice. Option C is preferred because it follows the typical convention of coarse-to-fine partition order.
Quick reference
AWS S3 Storage Class Comparison
| Storage Class | Min Duration | Retrieval | Use Case |
|---|---|---|---|
| S3 Standard | None | Immediate | Frequently accessed data |
| S3 Standard-IA | 30 days | Immediate | Infrequent access, rapid retrieval |
| S3 One Zone-IA | 30 days | Immediate | Non-critical infrequent data |
| S3 Intelligent-Tiering | None | Immediate–hours | Unknown or changing access patterns |
| S3 Glacier Instant | 90 days | Milliseconds | Archive with instant retrieval |
| S3 Glacier Flexible | 90 days | Minutes–hours | Archive, flexible retrieval |
| S3 Glacier Deep Archive | 180 days | Hours | Long-term compliance archive |
Go deeper
Related to this question
About these practice questions
This DEA-C01 question is part of Courseiva's 1,711-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DEA-C01 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DEA-C01 exam.