The answer is that the user was previously granted SELECT on the entire table, and the column-level GRANT did not revoke that broader permission. This is because Redshift’s column-level security operates on an additive model: a column-level GRANT only adds access for specific columns, but it never implicitly revokes any existing table-level privileges. If a user already holds SELECT on the whole table, they retain visibility into all columns, including those you intended to restrict. On the AWS Certified Database Specialty DBS-C01 exam, this scenario tests your understanding of how Redshift’s authorization hierarchy works—specifically that column-level controls are a refinement, not a replacement, for table-level grants. A common trap is assuming a column-level GRANT automatically overrides a prior table-level SELECT; in reality, you must explicitly REVOKE the table-level privilege first. Memory tip: “Additive access, never subtractive—revoke the table before you restrict the column.”
DBS-C01 Database Security Practice Question
This DBS-C01 practice question tests your understanding of database security. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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.
A company uses Amazon Redshift for data warehousing. The security team has implemented column-level security using Redshift's column-level access controls. However, during a security audit, it is discovered that a user with SELECT privilege on a table can still see the content of a column that should be restricted. The column is defined with a GRANT statement that only allows SELECT on certain columns to specific users. What is the most likely cause of this issue?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The user was previously granted SELECT on the entire table, and the column-level GRANT did not revoke that broader permission.
Option C is correct because column-level GRANTs in Redshift do not revoke existing permissions; they only add. If the user already had SELECT on the table, they still have access to all columns. Option A is not relevant. Option B is about views, not the issue. Option D is unrelated.
Key principle: Authentication proves identity; authorization controls what that identity can do after login. Both must work for full privileged access.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
The column is part of a distribution key that bypasses security controls.
Why it's wrong here
Distribution keys do not affect security.
✗
The user is accessing the table via a stored procedure that bypasses column-level security.
Why it's wrong here
Stored procedures run with definer's rights, but column-level security still applies.
✗
The column-level security is not supported in Redshift; it must be implemented using views.
Why it's wrong here
Redshift does support column-level GRANTs.
✓
The user was previously granted SELECT on the entire table, and the column-level GRANT did not revoke that broader permission.
Why this is correct
Column-level GRANTs are additive; they do not remove existing table-level permissions.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Authentication checks who the user is.
Common exam traps
Common exam trap: authentication is not authorization
Logging in proves the user can authenticate. It does not automatically mean the user is allowed to enter privileged or configuration mode. Watch for AAA authorization, privilege level and command authorization details.
Detailed technical explanation
How to think about this question
This kind of question is testing the difference between identity and permission. A user may successfully log in to a router because authentication is working, but still fail to enter configuration mode because authorization is missing, misconfigured or mapped to a lower privilege level.
KKey Concepts to Remember
Authentication checks who the user is.
Authorization controls what the user is allowed to do after login.
Privilege levels affect access to EXEC and configuration commands.
AAA, TACACS+ and RADIUS can separate login success from command access.
TExam Day Tips
→Do not assume successful login means full administrative access.
→Look for words such as cannot enter configuration mode, privilege level, authorization or command access.
→Separate login problems from permission problems before choosing the answer.
Key takeaway
Authentication proves identity; authorization controls what that identity can do after login. Both must work for full privileged access.
Real-world example
How this comes up in practice
A company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.
What to study next
Got this wrong? Here's your next step.
Review Cisco AAA concepts — authentication, authorization, and accounting. Study privilege levels (0–15), command authorization under TACACS+, and how RADIUS differs. Then practise related DBS-C01 questions on access control and AAA configuration.
Database Security — This question tests Database Security — Authentication checks who the user is..
What is the correct answer to this question?
The correct answer is: The user was previously granted SELECT on the entire table, and the column-level GRANT did not revoke that broader permission. — Option C is correct because column-level GRANTs in Redshift do not revoke existing permissions; they only add. If the user already had SELECT on the table, they still have access to all columns. Option A is not relevant. Option B is about views, not the issue. Option D is unrelated.
What should I do if I get this DBS-C01 question wrong?
Review Cisco AAA concepts — authentication, authorization, and accounting. Study privilege levels (0–15), command authorization under TACACS+, and how RADIUS differs. Then practise related DBS-C01 questions on access control and AAA configuration.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Authentication checks who the user is.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company is using Amazon Redshift for data warehousing. The security team requires column-level access control so that certain users cannot view specific columns containing PII. Which approach should the data engineer implement?
hard
✓ A.Create views that exclude the sensitive columns and grant SELECT on the views to the users.
B.Implement row-level security policies using CREATE ROW LEVEL SECURITY POLICY.
C.Use GRANT SELECT ON table (col1, col2) TO user.
D.Encrypt the sensitive columns using AWS KMS and decrypt in the application.
Why A: Option D is correct because Redshift supports column-level security via views that restrict columns, and you grant access to the view instead of the table. Option A is wrong because Redshift does not support column-level GRANT. Option B is wrong because row-level security does not restrict columns. Option C is wrong because column-level encryption is not natively supported in Redshift and would require application changes.
Last reviewed: Jun 20, 2026
Question Discussion
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This DBS-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 DBS-C01 exam.
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