Question 1
You have 20 Azure SQL databases provisioned by using the vCore purchasing model.
You plan to create an Azure SQL Database elastic pool and add the 20 databases.
Which three metrics should you use to size the elastic pool to meet the demands of your workload? Each correct answer presents part of the solution.
NOTE: Each correct selection is worth one point.
The AI assistant agrees with the suggested answer: A, C, and E.
Reason for choosing these answers:
When sizing an Azure SQL Database elastic pool in the vCore purchasing model, the goal is to optimize cost and performance by allocating shared resources effectively across a group of databases. The chosen metrics directly contribute to this optimization:
- A. total size of all the databases: This metric is crucial because an elastic pool provisions shared storage for all its databases. The total data size across all databases determines the minimum storage capacity required for the pool, which directly impacts the chosen service tier and its associated cost. It ensures that there is enough physical space for all database files.
- C. number of concurrently peaking databases * peak CPU utilization per database: This factor accounts for the worst-case scenario. Elastic pools are designed to handle fluctuating workloads, where individual databases might burst in resource usage. By multiplying the number of databases that peak simultaneously by their peak vCore (CPU) utilization, you determine the maximum aggregate compute capacity required by the pool at any given moment. This prevents performance bottlenecks during high-demand periods.
- E. total number of databases * average CPU utilization per database: This metric provides an understanding of the baseline or average compute demand of all databases combined. It helps in determining the sustained vCore capacity needed for the pool. Azure SQL Database elastic pools aim to average out resource consumption, and this metric contributes to defining the minimum and average vCore allocation. The total vCore allocation for the pool is typically the maximum of this average utilization and the concurrently peaking utilization (from option C), ensuring both baseline and peak demands are met efficiently.
Reason for not choosing the other answers:
- B. geo-replication support: While geo-replication is an important feature for disaster recovery and business continuity in Azure SQL Database, it is a configuration option and a cost adder for a *secondary* replica, not a metric used for *sizing the primary elastic pool's compute (vCore) or storage resources*. The capacity of the primary pool is determined by the workload it serves, not by whether it has geo-replication enabled for a secondary.
- D. maximum number of concurrent sessions for all the databases: The number of concurrent sessions is generally a consequence of the workload and the underlying compute (vCore/DTU) and I/O capacity. It is not a primary input metric for *sizing* the elastic pool's vCores or storage. The vCore and IOPS allocated to the pool will implicitly handle a certain number of sessions. Microsoft's official documentation for sizing elastic pools primarily focuses on resource utilization like CPU, memory, I/O, and storage, not directly on the number of concurrent sessions as a sizing criterion.
Citations:
- Monitor and size an Azure SQL Database elastic pool, https://learn.microsoft.com/en-us/azure/azure-sql/database/elastic-pool-monitoring-sizing
- Resource limits for elastic pools - Azure SQL Database, https://learn.microsoft.com/en-us/azure/azure-sql/database/sql-database-vcore-resource-limits-elastic-pools





