Paul Randal’s Wait Stats Script

I’m including this script just so I don’t need to hunt it down in the future… Paul is a very big brain in SQL Server. He worked in product engineering and owned the DBCC command and more.

From: http://www.sqlskills.com/blogs/paul/wait-statistics-or-please-tell-me-where-it-hurts/

 

WITH [Waits] AS
 (SELECT
 [wait_type],
 [wait_time_ms] / 1000.0 AS [WaitS],
 ([wait_time_ms] - [signal_wait_time_ms]) / 1000.0 AS [ResourceS],
 [signal_wait_time_ms] / 1000.0 AS [SignalS],
 [waiting_tasks_count] AS [WaitCount],
 100.0 * [wait_time_ms] / SUM ([wait_time_ms]) OVER() AS [Percentage],
 ROW_NUMBER() OVER(ORDER BY [wait_time_ms] DESC) AS [RowNum]
 FROM sys.dm_os_wait_stats
 WHERE [wait_type] NOT IN (
 N'BROKER_EVENTHANDLER', N'BROKER_RECEIVE_WAITFOR',
 N'BROKER_TASK_STOP', N'BROKER_TO_FLUSH',
 N'BROKER_TRANSMITTER', N'CHECKPOINT_QUEUE',
 N'CHKPT', N'CLR_AUTO_EVENT',
 N'CLR_MANUAL_EVENT', N'CLR_SEMAPHORE',
 N'DBMIRROR_DBM_EVENT', N'DBMIRROR_EVENTS_QUEUE',
 N'DBMIRROR_WORKER_QUEUE', N'DBMIRRORING_CMD',
 N'DIRTY_PAGE_POLL', N'DISPATCHER_QUEUE_SEMAPHORE',
 N'EXECSYNC', N'FSAGENT',
 N'FT_IFTS_SCHEDULER_IDLE_WAIT', N'FT_IFTSHC_MUTEX',
 N'HADR_CLUSAPI_CALL', N'HADR_FILESTREAM_IOMGR_IOCOMPLETION',
 N'HADR_LOGCAPTURE_WAIT', N'HADR_NOTIFICATION_DEQUEUE',
 N'HADR_TIMER_TASK', N'HADR_WORK_QUEUE',
 N'KSOURCE_WAKEUP', N'LAZYWRITER_SLEEP',
 N'LOGMGR_QUEUE', N'ONDEMAND_TASK_QUEUE',
 N'PWAIT_ALL_COMPONENTS_INITIALIZED',
 N'QDS_PERSIST_TASK_MAIN_LOOP_SLEEP',
 N'QDS_CLEANUP_STALE_QUERIES_TASK_MAIN_LOOP_SLEEP',
 N'REQUEST_FOR_DEADLOCK_SEARCH', N'RESOURCE_QUEUE',
 N'SERVER_IDLE_CHECK', N'SLEEP_BPOOL_FLUSH',
 N'SLEEP_DBSTARTUP', N'SLEEP_DCOMSTARTUP',
 N'SLEEP_MASTERDBREADY', N'SLEEP_MASTERMDREADY',
 N'SLEEP_MASTERUPGRADED', N'SLEEP_MSDBSTARTUP',
 N'SLEEP_SYSTEMTASK', N'SLEEP_TASK',
 N'SLEEP_TEMPDBSTARTUP', N'SNI_HTTP_ACCEPT',
 N'SP_SERVER_DIAGNOSTICS_SLEEP', N'SQLTRACE_BUFFER_FLUSH',
 N'SQLTRACE_INCREMENTAL_FLUSH_SLEEP',
 N'SQLTRACE_WAIT_ENTRIES', N'WAIT_FOR_RESULTS',
 N'WAITFOR', N'WAITFOR_TASKSHUTDOWN',
 N'WAIT_XTP_HOST_WAIT', N'WAIT_XTP_OFFLINE_CKPT_NEW_LOG',
 N'WAIT_XTP_CKPT_CLOSE', N'XE_DISPATCHER_JOIN',
 N'XE_DISPATCHER_WAIT', N'XE_TIMER_EVENT')
 AND [waiting_tasks_count] > 0
 )
SELECT
 MAX ([W1].[wait_type]) AS [WaitType],
 CAST (MAX ([W1].[WaitS]) AS DECIMAL (16,2)) AS [Wait_S],
 CAST (MAX ([W1].[ResourceS]) AS DECIMAL (16,2)) AS [Resource_S],
 CAST (MAX ([W1].[SignalS]) AS DECIMAL (16,2)) AS [Signal_S],
 MAX ([W1].[WaitCount]) AS [WaitCount],
 CAST (MAX ([W1].[Percentage]) AS DECIMAL (5,2)) AS [Percentage],
 CAST ((MAX ([W1].[WaitS]) / MAX ([W1].[WaitCount])) AS DECIMAL (16,4)) AS [AvgWait_S],
 CAST ((MAX ([W1].[ResourceS]) / MAX ([W1].[WaitCount])) AS DECIMAL (16,4)) AS [AvgRes_S],
 CAST ((MAX ([W1].[SignalS]) / MAX ([W1].[WaitCount])) AS DECIMAL (16,4)) AS [AvgSig_S]
FROM [Waits] AS [W1]
INNER JOIN [Waits] AS [W2]
 ON [W2].[RowNum] <= [W1].[RowNum]
GROUP BY [W1].[RowNum]
HAVING SUM ([W2].[Percentage]) - MAX ([W1].[Percentage]) < 95; -- percentage threshold
GO

 

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