DP-300 Practice Question: Monitor, configure, and optimize database resources
You are the database administrator for a hybrid environment with on-premises SQL Server 2022 and Azure SQL Database. All databases use the AdventureWorks schema. You notice that a critical stored procedure runs slower on Azure SQL Database than on-premises. Both have identical indexes and statistics. What is the most likely cause?
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 version of the cardinality estimator differs between environments.
The cardinality estimator (CE) version can differ between on-premises SQL Server and Azure SQL Database, even with identical indexes and statistics. The CE version is determined by the database compatibility level, and Azure SQL Database may have a different default compatibility level than on-prem, leading to different query plans and performance. Option B is incorrect because DTU vs vCore is a purchasing model that does not inherently slow queries; it affects resource limits but not plan choices. Option C is incorrect because automatic tuning in Azure SQL Database typically helps performance, and index fragmentation levels would be similar with identical indexes. Option D is incorrect because intelligent query processing features are available on both platforms and generally beneficial, not detrimental.
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 version of the cardinality estimator differs between environments.
Why this is correct
On-prem SQL Server 2022 may use legacy CE, while Azure SQL Database uses default CE, leading to different plans.
- ✗
Azure SQL Database uses a different resource governance model (DTU vs vCore).
Why it's wrong here
Resource governance affects throughput but not query plan choice.
- ✗
The index fragmentation level is higher on Azure SQL Database due to automatic tuning.
Why it's wrong here
Automatic tuning does not cause fragmentation; fragmentation would affect both similarly if indexes are same.
- ✗
Azure SQL Database has intelligent query processing features that are not available on-premises.
Why it's wrong here
IQP is available in both SQL Server 2022 and Azure SQL Database; differences are minimal.
Go deeper
Related to this question
Learn chapter
Overview of Azure Data Platform Options
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.
About these practice questions
This DP-300 question is part of Courseiva's 906-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-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.