DEA-C01 Data Ingestion and Transformation Practice Question
A data engineer is setting up a data ingestion pipeline using Amazon Kinesis Data Firehose to deliver web server logs to Amazon S3. The logs are in JSON format and the engineer wants to convert them to Parquet format. The engineer has configured a Glue table for the schema. However, when testing, the Firehose delivery stream fails with 'Error converting to Parquet'. The engineer checks the Glue table schema and notices that it includes a column 'timestamp' of type 'string' in the format 'yyyy-MM-dd HH:mm:ss'. The logs have a 'timestamp' field in the same format. What is the MOST likely cause of the failure?
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
✓
The Glue table schema does not match the data schema exactly.
The failure is most likely due to a schema mismatch between the Glue table and the actual data. Firehose uses the Glue table schema to convert JSON to Parquet, and if the schema does not exactly match (e.g., column order, data types, or extra columns), the conversion fails. Option A is incorrect because Firehose does support Parquet conversion when a Glue table is provided. Option C is incorrect because S3 permissions would cause a different error (e.g., AccessDenied). Option D is incorrect because a string type for timestamp is acceptable as long as it matches; the issue is not the type but the overall schema mismatch.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Firehose does not support Parquet conversion.
Why it's wrong here
Firehose supports Parquet conversion.
- ✓
The Glue table schema does not match the data schema exactly.
Why this is correct
Mismatch between schema and data causes conversion failure.
- ✗
The S3 bucket lacks write permissions for Firehose.
Why it's wrong here
Write permissions would cause a different error.
- ✗
The 'timestamp' column must be of type 'timestamp' instead of 'string'.
Why it's wrong here
String type can be used for conversion.
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
Courseiva writes every DEA-C01 question from scratch — 1,711 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or 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.