DTU vs vCore pricing models in Azure - Practice Questions

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding DTU Pricing Model

Which statement best describes the DTU pricing model for Azure SQL Database?

A DTU pricing allows unlimited scaling without additional cost.

B DTU pricing charges separately for compute and storage resources.

C DTU pricing is based solely on the number of CPU cores used.

D DTU bundles compute, memory, and I/O resources into a single unit for simplified pricing.

💡 Hint

Think about how DTU combines different resources into one unit.

DTU (Database Transaction Unit) is a blended measure of CPU, memory, and I/O resources bundled together for simplified pricing.

❓ Architecture

intermediate

Choosing Between DTU and vCore Models

You need to select a pricing model for an Azure SQL Database that requires predictable performance and flexibility to scale compute and storage independently. Which pricing model fits best?

A DTU model, because it charges separately for compute and storage.

B DTU model, because it bundles all resources for simplicity.

C vCore model, because it allows independent scaling of compute and storage.

D vCore model, because it bundles compute, memory, and I/O into one unit.

💡 Hint

Consider which model offers separate scaling of resources.

The vCore model allows you to scale compute and storage independently, providing more flexibility and predictable pricing.

❓ service_behavior

advanced

Impact of Scaling Storage in DTU vs vCore Models

What happens when you increase storage size in the DTU pricing model compared to the vCore pricing model?

A In DTU, increasing storage automatically increases DTUs and cost; in vCore, storage scales independently with separate cost.

B In DTU, storage scales independently with no cost change; in vCore, storage increase raises compute cost.

C Both DTU and vCore models increase compute resources automatically when storage increases.

D Neither DTU nor vCore models charge for storage increases.

💡 Hint

Think about how storage and compute are linked in each model.

DTU bundles compute and storage, so increasing storage often increases DTUs and cost. vCore separates storage cost, so you pay only for added storage.

❓ security

advanced

Security Considerations in DTU vs vCore Models

Which statement correctly describes security features availability between DTU and vCore pricing models?

A vCore model supports advanced security features like Azure Defender and Always Encrypted, while DTU does not.

B DTU model supports all advanced security features, but vCore model does not.

C Both DTU and vCore models support the same security features without differences.

D DTU model supports Azure Defender, but vCore model requires manual configuration for security.

💡 Hint

Consider which model is newer and supports more advanced features.

The vCore model supports the latest advanced security features such as Azure Defender and Always Encrypted, while DTU is more limited.

✅ Best Practice

expert

Optimizing Cost with vCore Model for Variable Workloads

You have an Azure SQL Database workload with fluctuating compute needs but steady storage requirements. Which approach best optimizes cost using the vCore pricing model?

A Provision minimal vCores and increase storage size to compensate for compute spikes.

B Use serverless compute tier to auto-scale compute and provision fixed storage size.

C Provision high compute vCores permanently and scale storage as needed.

D Use DTU model instead because it bundles compute and storage for fluctuating workloads.

💡 Hint

Think about how to handle variable compute needs cost-effectively.

The serverless compute tier in the vCore model automatically scales compute based on workload demand, while storage remains fixed, optimizing cost for variable workloads.

Practice

1. What does the DTU pricing model in Azure SQL Database combine into a single unit?

easy

A. Only memory resources

B. Only CPU resources

C. Storage and network bandwidth

D. CPU, memory, and I/O resources bundled together

Solution

1. Step 1: Understand DTU components

   DTU stands for Database Transaction Unit, which bundles CPU, memory, and I/O into one unit for simple pricing.

2. Step 2: Compare options to DTU definition

   Only CPU, memory, and I/O resources bundled together correctly lists CPU, memory, and I/O bundled together.

3. Final Answer:

   CPU, memory, and I/O resources bundled together -> Option D

4. Quick Check:

   DTU = bundled CPU, memory, I/O [OK]

Hint: DTU bundles CPU, memory, and I/O as one unit [OK]

Common Mistakes:

• Thinking DTU is only CPU or memory
• Confusing DTU with storage pricing
• Assuming DTU separates resources

2. Which of the following is the correct way to describe the vCore pricing model?

easy

A. It lets you select CPU and memory separately

B. It bundles CPU, memory, and I/O into one unit

C. It charges only for storage used

D. It is only available for on-premises databases

Solution

1. Step 1: Recall vCore pricing features

   The vCore model allows choosing CPU and memory independently for more control over resources.

2. Step 2: Match options to vCore traits

   It lets you select CPU and memory separately correctly states that CPU and memory are selected separately, unlike DTU.

3. Final Answer:

   It lets you select CPU and memory separately -> Option A

4. Quick Check:

   vCore = separate CPU and memory selection [OK]

Hint: vCore separates CPU and memory choices [OK]

Common Mistakes:

• Confusing vCore with DTU bundling
• Thinking vCore charges only storage
• Assuming vCore is for on-premises only

3. If a workload requires high CPU but moderate memory, which pricing model is better to optimize cost?

medium

A. vCore model because you can choose more CPU and less memory

B. DTU model because it bundles all resources

C. DTU model because it charges separately for CPU

D. vCore model because it bundles CPU and memory

Solution

1. Step 1: Analyze workload needs

   The workload needs high CPU but only moderate memory, so flexibility in resource selection is important.

2. Step 2: Compare pricing models for flexibility

   DTU bundles CPU and memory, so you cannot adjust them separately. vCore lets you pick CPU and memory independently, optimizing cost.

3. Final Answer:

   vCore model because you can choose more CPU and less memory -> Option A

4. Quick Check:

   High CPU + moderate memory = vCore better [OK]

Hint: Choose vCore for flexible CPU and memory [OK]

Common Mistakes:

• Choosing DTU for flexible resource needs
• Thinking DTU charges CPU separately
• Confusing bundling in vCore

4. A user selects the DTU pricing model but wants to increase only memory without changing CPU. What is the issue?

medium

A. DTU allows only CPU scaling, not memory

B. DTU does not allow separate scaling of CPU and memory

C. DTU charges extra for memory upgrades only

D. DTU automatically scales memory without user input

Solution

1. Step 1: Understand DTU scaling limits

   DTU bundles CPU, memory, and I/O, so you cannot scale memory independently without affecting CPU.

2. Step 2: Identify the problem with user's request

   The user wants to increase only memory, which DTU does not support because of bundled resources.

3. Final Answer:

   DTU does not allow separate scaling of CPU and memory -> Option B

4. Quick Check:

   DTU = no separate CPU/memory scaling [OK]

Hint: DTU bundles resources; no separate scaling [OK]

Common Mistakes:

• Thinking DTU allows memory-only scaling
• Assuming DTU charges extra for memory only
• Believing DTU auto-scales memory

5. A company has a workload with unpredictable spikes in CPU and memory usage. They want to minimize cost but maintain performance. Which pricing model and strategy should they choose?

hard

A. Use DTU model with a high DTU level to cover spikes

B. Use vCore model but fix CPU and memory to lowest levels

C. Use vCore model with autoscaling to adjust CPU and memory dynamically

D. Use DTU model and manually upgrade when spikes occur

Solution

1. Step 1: Analyze workload characteristics

   The workload has unpredictable spikes in CPU and memory, requiring flexible resource adjustment to maintain performance.

2. Step 2: Evaluate pricing models and strategies

   DTU bundles resources and requires fixed levels, so it is less flexible and may lead to overpaying. vCore supports autoscaling, allowing dynamic adjustment of CPU and memory to match demand and minimize cost.

3. Step 3: Choose best option

   Use vCore model with autoscaling to adjust CPU and memory dynamically uses vCore with autoscaling, which fits the need for flexibility and cost control.

4. Final Answer:

   Use vCore model with autoscaling to adjust CPU and memory dynamically -> Option C

5. Quick Check:

   Unpredictable spikes = vCore + autoscaling [OK]

Hint: Autoscale CPU and memory with vCore for spikes [OK]

Common Mistakes:

• Choosing fixed DTU for variable workloads
• Manually upgrading DTU causing delays
• Fixing vCore resources too low