DEA-C01 Data Operations and Support Practice Question
A data engineer is troubleshooting a Glue ETL job that reads from an S3 bucket and writes to a Redshift table. The job fails with a 'MemoryError' when processing a large dataset. Which TWO actions should the engineer take to resolve this issue? (Choose TWO.)
⚠ Common exam trap
Candidates often confuse 'coalesce(1)' (which reduces parallelism) with a memory-saving technique, or mistakenly think decreasing DPUs or adjusting RedshiftTempDir can fix memory errors, when in fact memory errors require more resources and better partition management.
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
✓
Increase the number of DPUs and set 'spark.sql.shuffle.partitions' to a higher value.
Increasing the number of DPUs (Data Processing Units) provides more memory and compute resources to the Glue job, directly addressing the MemoryError. Setting 'spark.sql.shuffle.partitions' to a higher value reduces the amount of data shuffled per partition, preventing out-of-memory errors during wide transformations like joins or aggregations.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Increase the number of DPUs and set 'spark.sql.shuffle.partitions' to a higher value.
Why this is correct
More DPUs and shuffle partitions distribute data across more executors, reducing per-executor memory load.
- ✗
Increase the number of DPUs and set 'coalesce(1)' in the script.
Why it's wrong here
coalesce(1) reduces parallelism, increasing memory pressure on a single executor.
- ✗
Decrease the number of DPUs and increase 'spark.shuffle.partitions'.
Why it's wrong here
Decreasing DPUs reduces available memory, worsening the problem.
- ✗
Set the 'RedshiftTempDir' parameter to a larger S3 bucket.
Why it's wrong here
RedshiftTempDir is for staging data, not for resolving memory errors in Glue.
- ✓
Set the 'groupFiles' option to 'inPartition' in the S3 source configuration.
Why this is correct
groupFiles combines small files into larger partitions, reducing overhead and memory pressure.
Visual reference
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
One of 1,711 original DEA-C01 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. 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.