DP-900 Describe core data concepts Practice Question
A company uses Azure Data Lake Storage Gen2 for a data lake. They implement a folder structure with access control lists (ACLs). A new data scientist needs to read data from a specific folder but not write to it. Which ACL permission should be assigned?
⚠ Common exam trap
Candidates often assume Read permission on a folder is sufficient to read its contents, but without Execute permission, the folder cannot be traversed, making the data inaccessible.
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
✓
Execute
Execute (X) permission on a folder in Azure Data Lake Storage Gen2 is required to traverse the folder and access its contents. Without Execute, a user cannot list or read files inside the folder, even if Read permission is granted. Since the data scientist only needs to read data (not write), assigning Execute on the folder and Read on the files allows traversal and read access without write capability.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Execute
Why this is correct
The execute (x) permission on a directory allows a user to traverse through that directory when resolving a path. In ADLS Gen2's POSIX-style ACLs, execute on each folder in the hierarchy is mandatory to reach a file in a subfolder; once the user also has read permission on the target file, they can open and read its contents. Without execute on the folder, the user cannot pass through it, even if the file's own read bit is set.
- ✗
Modify
Why it's wrong here
Modify is not a native POSIX ACL permission in Azure Data Lake Storage Gen2; where tools expose it, it acts as a composite right that bundles read, write, and delete/remove actions. Granting Modify on a folder would let the user create, overwrite, or delete files inside it, which goes far beyond the minimal, traverse-only access needed to read data. This violates least privilege and can lead to unintended data changes or loss, so Execute is the correct choice.
- ✗
Write
Why it's wrong here
Write (w) on a folder controls changes to the directory's contents, such as creating new files or deleting existing entries, but it does not grant the right to traverse the folder hierarchy. A user with Write but no Execute cannot move through the directory to reach nested files, and Write provides no ability to open an existing file for reading. Thus Write is oriented toward data modification and creation, not toward passing through a path to read data.
- ✗
Read
Why it's wrong here
Read (r) on a folder in ADLS Gen2 POSIX ACLs permits listing the names of entries in that folder, but it does not allow opening or accessing those entries. To actually traverse the directory and resolve a path to a file, the execute (x) permission is also required; with only Read, the path lookup is blocked and the user cannot reach files in that folder or its subfolders. Therefore Read alone cannot read file contents—Execute must be granted on the folder as well.
Visual reference
Go deeper
Related to this question
Learn chapter
Data Roles and Core Concepts
Key term
Data Lake Storage Gen2
Data Lake Storage Gen2 is a cloud-based storage service that combines a scalable data lake with enterprise-grade file system capabilities for big data analytics.
Key term
Data lake
A data lake is a centralized storage repository that holds vast amounts of raw data in its native format until it is needed for analysis.
About these practice questions
This DP-900 question is part of Courseiva's 820-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 DP-900 practice question is part of Courseiva's free Microsoft 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 DP-900 exam.