Updated sys.dm_os_waiting_tasks script to correctly parse nodeId

I realized that I’d fixed an issue with my sys.dm_os_waiting_tasks script to correctly parse out the parallelism nodeId from the resource_description column (as newer versions include more info after the nodeId=X info) but I never blogged the update. Here it is for your use(and all other references have been updated to point to this post).

Enjoy!

(Note that ‘text’ on one line does not have delimiters because that messes up the code formatting plugin):

/*============================================================================
  File:     WaitingTasks.sql

  Summary:  Snapshot of waiting tasks

  SQL Server Versions: 2005 onward
------------------------------------------------------------------------------
  Written by Paul S. Randal, SQLskills.com

  (c) 2019, SQLskills.com. All rights reserved.

  For more scripts and sample code, check out 
    http://www.SQLskills.com

  You may alter this code for your own *non-commercial* purposes. You may
  republish altered code as long as you include this copyright and give due
  credit, but you must obtain prior permission before blogging this code.
  
  THIS CODE AND INFORMATION ARE PROVIDED "AS IS" WITHOUT WARRANTY OF 
  ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED 
  TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
  PARTICULAR PURPOSE.
============================================================================*/
SELECT
    [owt].[session_id] AS [SPID],
    [owt].[exec_context_id] AS [Thread],
    [ot].[scheduler_id] AS [Scheduler],
    [owt].[wait_duration_ms] AS [wait_ms],
    [owt].[wait_type],
    [owt].[blocking_session_id] AS [Blocking SPID],
    [owt].[resource_description],
    CASE [owt].[wait_type]
        WHEN N'CXPACKET' THEN
            SUBSTRING ( -- earlier versions don't have anything after the nodeID...
                [owt].[resource_description],
                CHARINDEX (N'nodeId=', [owt].[resource_description]) + 7,
                CHARINDEX (N' tid=', [owt].[resource_description] + ' tid=') -
                    CHARINDEX (N'nodeId=', [owt].[resource_description]) - 7
            )
        ELSE NULL
    END AS [Node ID],
    [eqmg].[dop] AS [DOP],
    [er].[database_id] AS [DBID],
    CAST ('https://www.sqlskills.com/help/waits/' + [owt].[wait_type] as XML) AS [Help/Info URL],
    [eqp].[query_plan],
    [est].text
FROM sys.dm_os_waiting_tasks [owt]
INNER JOIN sys.dm_os_tasks [ot] ON
    [owt].[waiting_task_address] = [ot].[task_address]
INNER JOIN sys.dm_exec_sessions [es] ON
    [owt].[session_id] = [es].[session_id]
INNER JOIN sys.dm_exec_requests [er] ON
    [es].[session_id] = [er].[session_id]
FULL JOIN sys.dm_exec_query_memory_grants [eqmg] ON
    [owt].[session_id] = [eqmg].[session_id]
OUTER APPLY sys.dm_exec_sql_text ([er].[sql_handle]) [est]
OUTER APPLY sys.dm_exec_query_plan ([er].[plan_handle]) [eqp]
WHERE
    [es].[is_user_process] = 1
ORDER BY
    [owt].[session_id],
    [owt].[exec_context_id];
GO

One thought on “Updated sys.dm_os_waiting_tasks script to correctly parse nodeId

  1. Very cool script, found my lack of memory issue. PC has 16 GB of RAM
    An alter index , create index , even a DBCC CHECKDB would run for 2 minutes or 5 seconds then Disk I/O slowed right down to ZERO.

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