Question 445 of 1,755
Data EngineeringmediumMultiple ChoiceObjective-mapped

MLS-C01 Data Engineering Practice Question

This MLS-C01 practice question tests your understanding of data engineering. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.

Network Topology
aws s3api head-objectbucket my-data-lakekey logs/2024/01/15/app.logRefer to the exhibit.```"LastModified": "2024-01-15T12:30:00Z","ContentLength": 2048,"ETag": "\"abc123\"","ContentType": "application/octet-stream","Metadata": {"kafka-offset": "12345"

A data engineer runs the AWS CLI command above to inspect an object in S3. The engineer wants to query this metadata (kafka-offset) using Amazon Athena to track processing progress. How can the engineer make this metadata available for Athena queries without modifying the existing data pipeline?

Network Topology
aws s3api head-objectbucket my-data-lakekey logs/2024/01/15/app.logRefer to the exhibit.```"LastModified": "2024-01-15T12:30:00Z","ContentLength": 2048,"ETag": "\"abc123\"","ContentType": "application/octet-stream","Metadata": {"kafka-offset": "12345"

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 AWS Glue to create a table that includes the metadata as a column by running an ETL job.

Option C is correct because AWS Glue ETL jobs can read the S3 object's user-defined metadata (e.g., 'kafka-offset') and write it as a column in a new or transformed dataset, which Athena can then query. This approach does not modify the existing data pipeline, as the original objects remain unchanged; the metadata is extracted and stored in a queryable format (e.g., Parquet or CSV) in a separate location. Glue's ability to access S3 object metadata via the `getObjectMetadata` API during ETL processing makes this a clean, pipeline-agnostic solution.

Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

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 S3 object tags instead of metadata and query the tags using Athena.

    Why it's wrong here

    Athena does not query S3 object tags.

  • Use an AWS Lambda function to copy the metadata into the object's content as a new line.

    Why it's wrong here

    Modifying object content would change the data and is not recommended.

  • Use AWS Glue to create a table that includes the metadata as a column by running an ETL job.

    Why this is correct

    A Glue ETL job can read objects, extract metadata, and write to a table that Athena can query.

    Related concept

    Read the scenario before looking for a memorised answer.

  • Use Amazon Athena to query the object metadata directly by referencing the metadata field.

    Why it's wrong here

    Athena cannot query S3 object metadata directly.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates assume Athena can natively query S3 object metadata (like HTTP headers) because Athena can query data in S3, but Athena has no access to object-level metadata—it only reads the content of files, not the object's key-value metadata fields.

Detailed technical explanation

How to think about this question

Under the hood, S3 user-defined metadata is stored as HTTP headers (x-amz-meta-*) and is not part of the object's byte content; Athena's Presto/Trino engine reads only the data within the object, not its headers. AWS Glue ETL jobs can use the `boto3` `head_object` or `get_object` calls to retrieve metadata and then write it as a column, enabling schema-on-read queries. In real-world streaming pipelines, this pattern is used to track offsets without reprocessing raw data, as the metadata can be stored in a separate 'metadata catalog' table in the Glue Data Catalog.

KKey Concepts to Remember

  • Read the scenario before looking for a memorised answer.
  • Find the constraint that changes the correct option.
  • Eliminate answers that are true in general but not in this case.

TExam Day Tips

  • Watch for words such as best, first, most likely and least administrative effort.
  • Review why wrong options are wrong, not only why the correct option is correct.

Key takeaway

Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

Real-world example

How this comes up in practice

A media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.

Quick reference

AWS S3 Storage Class Comparison

Storage ClassMin DurationRetrievalUse Case
S3 StandardNoneImmediateFrequently accessed data
S3 Standard-IA30 daysImmediateInfrequent access, rapid retrieval
S3 One Zone-IA30 daysImmediateNon-critical infrequent data
S3 Intelligent-TieringNoneImmediate–hoursUnknown or changing access patterns
S3 Glacier Instant90 daysMillisecondsArchive with instant retrieval
S3 Glacier Flexible90 daysMinutes–hoursArchive, flexible retrieval
S3 Glacier Deep Archive180 daysHoursLong-term compliance archive

What to study next

Got this wrong? Here's your next step.

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

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FAQ

Questions learners often ask

What does this MLS-C01 question test?

Data Engineering — This question tests Data Engineering — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Use AWS Glue to create a table that includes the metadata as a column by running an ETL job. — Option C is correct because AWS Glue ETL jobs can read the S3 object's user-defined metadata (e.g., 'kafka-offset') and write it as a column in a new or transformed dataset, which Athena can then query. This approach does not modify the existing data pipeline, as the original objects remain unchanged; the metadata is extracted and stored in a queryable format (e.g., Parquet or CSV) in a separate location. Glue's ability to access S3 object metadata via the `getObjectMetadata` API during ETL processing makes this a clean, pipeline-agnostic solution.

What should I do if I get this MLS-C01 question wrong?

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

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Last reviewed: Jul 4, 2026

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This MLS-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 MLS-C01 exam.