DP-300 Implement a secure environment Practice Question
Your company has a strict policy that Azure SQL Database backups must be encrypted with customer-managed keys stored in Azure Key Vault. You configure TDE with AKV integration. After a key rotation, you find that long-running queries start failing with encryption errors. What is the most likely cause?
⚠ Common exam trap
Watch out — candidates often assume key rotation is seamless and never causes failures, overlooking that disabling or deleting the previous key version can break in-flight operations that still depend on it.
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
✓
The previous key version was disabled or deleted in AKV.
When TDE is configured with Azure Key Vault (AKV) integration, the database uses the current key version from AKV to encrypt and decrypt data. If the previous key version is disabled or deleted during a key rotation, any long-running queries that still rely on that specific key version for decryption will fail with encryption errors. The database cannot automatically fall back to the new key version for in-flight operations that started before the rotation.
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 service principal used for AKV access has expired.
Why it's wrong here
Permission issues would cause access denied errors, not encryption errors.
- ✓
The previous key version was disabled or deleted in AKV.
Why this is correct
TDE requires all previous key versions to be enabled to decrypt existing data.
- ✗
The new key is in a different Azure region than the database.
Why it's wrong here
AKV keys can be in any region; region mismatch is not an issue.
- ✗
The database is using service-managed TDE and cannot switch to customer-managed keys.
Why it's wrong here
The error occurred after rotation, not during initial setup.
Go deeper
Related to this question
Learn chapter
Overview of Azure Data Platform Options
Key term
Transparent Data Encryption
Transparent Data Encryption is a security feature that automatically encrypts data written to a database and decrypts it when read, without requiring any changes to the application.
Key term
Azure SQL Performance Tuning
Azure SQL Performance Tuning is the process of optimizing the speed and efficiency of queries and database operations in Microsoft Azure SQL Database or SQL Managed Instance to reduce latency and improve throughput.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DP-300 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-300 exam.