MLA-C01 Data Preparation for Machine Learning Practice Question
A data scientist is exploring data stored in an Amazon Redshift cluster. The data includes timestamp columns with different formats. The scientist wants to create a new column that standardizes the timestamp format to UTC. Which approach is MOST efficient?
⚠ Common exam trap
It's easy for candidates to assume external ETL tools (Glue, SageMaker) are always necessary for complex transforms, overlooking Redshift's powerful built-in SQL functions that can perform the same task with zero data egress.
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
✓
Use a SELECT with CONVERT_TIMEZONE in Redshift and export to S3
`CONVERT_TIMEZONE` in Amazon Redshift is a native SQL function that directly converts timestamps to UTC without moving data outside the cluster. This approach avoids the overhead of external services, leverages Redshift's massively parallel processing (MPP) engine, and is the most efficient for in-database transformations.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Use AWS Glue to read the Redshift table and apply a custom transform
Why it's wrong here
Glue adds overhead and requires data movement.
- ✓
Use a SELECT with CONVERT_TIMEZONE in Redshift and export to S3
Why this is correct
CONVERT_TIMEZONE is a built-in Redshift function that efficiently converts timestamps.
- ✗
Use a SageMaker notebook to query Redshift and transform
Why it's wrong here
Notebooks are not ideal for production-scale transformation.
- ✗
Use Amazon QuickSight to transform the timestamp
Why it's wrong here
QuickSight is for visualization, not data transformation.
Go deeper
Related to this question
About these practice questions
Courseiva writes every MLA-C01 question from scratch — 835 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 MLA-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 MLA-C01 exam.