AZ-305 Question 64
Single answerYou are designing an Azure SQL Database for a new order processing application. The database is expected to remain well under 1 TB for at least two years, but usage patterns are highly unpredictable. There will be periods of minimal activity and occasional spikes during monthly order reconciliation. The business wants to minimize costs when idle while ensuring that the solution scales quickly during peak usage. Which Azure SQL Database service tier and compute tier combination best meets these requirements?
- A
Basic tier (DTU-based)
- B
Business Critical tier (provisioned compute)
- C
Hyperscale tier (provisioned compute)
- D
General Purpose tier (serverless compute)
Show answer and explanation
Correct answer: D
Explanation
In Azure SQL Database, serverless compute is only available in the General Purpose tier. It automatically scales up and down based on current demand, and it pauses (bills only for storage) when there is no activity, making it highly cost-effective for workloads with unpredictable or intermittent usage. Microsoft documentation recommends the General Purpose tier with serverless compute for scenarios in which the database size does not exceed several terabytes and where cost savings during idle times is a priority.
- A. Incorrect.
Option 1: Basic tier (DTU-based), INCORRECT. While it is low-cost, the Basic tier is typically intended for very small or development workloads. It does not automatically scale to handle sudden spikes, and it does not provide the cost-optimization features of serverless.
- B. Incorrect.
Option 2: Business Critical tier (provisioned compute), INCORRECT. This tier provides high performance and low latency for mission-critical applications, but it does not support serverless. It would result in higher costs even during idle periods, which contradicts the cost minimization requirement.
- C. Incorrect.
Option 3: Hyperscale tier (provisioned compute), INCORRECT. While Hyperscale supports databases up to 100 TB and is ideal for very large data growth, it does not offer serverless compute. This makes it less cost-efficient during extended idle times for databases that will remain under 1 TB.
- D. Correct.
Option 4: General Purpose tier (serverless compute), CORRECT. Serverless compute automatically scales based on workload and pauses billing for compute during idle periods, reducing costs. Since the database is not projected to exceed 1 TB in the near future, General Purpose tier with serverless compute is an ideal fit.