You have a Microsoft Azure SQL database. Users report that queries to the database take longer than expected to complete. You need to identify the amount of CPU resources that the database used…

While the Azure portal provides a user-friendly interface to view historical CPU usage trends, the question implies a more direct method of identifying the underlying resource usage, which is done by querying the database engine's performance counters. The portal itself relies on collecting these metrics from the database.

The `sys.dm_os_performance_counters` dynamic management view exposes real-time performance counters within the SQL Server engine, including various metrics for CPU usage. While it provides current values, these counters are the foundational data points that must be collected and aggregated over time to analyze CPU resource consumption trends, such as usage over the last week.

Microsoft System Center is a suite of management products, not a direct tool for querying an Azure SQL database's performance metrics; it would rely on agents or connectors that, in turn, query DMVs or Azure Monitor.

Performance Monitor (Perfmon) is a Windows-based tool primarily for monitoring local or remote Windows servers and cannot directly connect to and monitor an Azure SQL database, which is a platform-as-a-service offering.