等待大概分为3类:资源等待、队列等待、外部等待
过滤掉系统相关的等待类型的语句。(查看常用的等待信息)
SELECT wait_type , signal_wait_time_ms , wait_time_ms FROM sys.dm_os_wait_stats WHERE wait_time_ms > 0 AND wait_type NOT IN ( 'CLR_SEMAPHORE', 'CLR_AUTO_EVENT', 'LAZYWRITER_SLEEP', 'RESOURCE_QUEUE', 'SLEEP_TASK', 'SLEEP_SYSTEMTASK', 'SQLTRACE_BUFFER_FLUSH', 'WAITFOR', 'LOGMGR_QUEUE', 'CHECKPOINT_QUEUE', 'REQUEST_FOR_DEADLOCK_SEARCH', 'XE_TIMER_EVENT', 'BROKER_TO_FLUSH', 'BROKER_TASK_STOP', 'CLR_MANUAL_EVENT', 'DISPATCHER_QUEUE_SEMAPHORE', 'FT_IFTS_SCHEDULER_IDLE_WAIT', 'XE_DISPATCHER_WAIT', 'XE_DISPATCHER_JOIN', 'SQLTRACE_INCREMENTAL_FLUSH_SLEEP' ) ORDER BY signal_wait_time_ms DESC
生产环境中使用:
DBCC SQLPERF('sys.dm_os_wait_stats',CLEAR)