SQLServer 数据库维护指南：精准测量最近 N 分钟 CPU 使用率

（此脚本为网络参考，出处不详）

DECLARE @ts_now bigint = (SELECT cpu_ticks/(cpu_ticks/ms_ticks)  
FROM sys.dm_os_sys_info WITH (NOLOCK));  
--	前N行则表示最近的N分钟内CPU使用情况
SELECT TOP(60) 
 DATEADD(ms, -1 * (@ts_now - [timestamp]), GETDATE()) AS [Event Time]  
,SQLProcessUtilization AS [SQL Server Process CPU Utilization]
,SystemIdle AS [System Idle Process]
,(100 - SystemIdle - SQLProcessUtilization) AS [Other Process CPU Utilization]
FROM (
	SELECT record.value('(./Record/@id)[1]', 'int') AS record_id
	,record.value('(./Record/SchedulerMonitorEvent/SystemHealth/SystemIdle)[1]', 'int') AS[SystemIdle]
	,record.value('(./Record/SchedulerMonitorEvent/SystemHealth/ProcessUtilization)[1]','int') AS [SQLProcessUtilization], [timestamp]  
	FROM (
		SELECT [timestamp], CONVERT(xml, record) AS [record]  
		FROM sys.dm_os_ring_buffers WITH (NOLOCK)  
		WHERE ring_buffer_type = N'RING_BUFFER_SCHEDULER_MONITOR'  
		AND record LIKE N'%<SystemHealth>%'
	) AS x  
) AS y  
ORDER BY record_id DESC OPTION (RECOMPILE);