BI SQL # 204 : SQL Server DBA Scripts : Identify Top Nth waits With I / O Specification

Hi Folks,

In this article we are going to cover How to Identify Top Nth waits With I / O Specification.

In this post we are going to discuss following points:

• Problem Statement of SQL Script:
• Description of SQL Script:
• SQL Script Output Column
• SQL Script Code
• SQL Script Output Screenshot
• User Level to execute

Problem Statement of SQL Script:

How to Identify Top Nth waits With I / O Specification ?

Description of SQL Script:

This script will help to identify top Nth waits With I / O Specification.

SQL Script Output Column

SQL Script Code

WITH Waits
AS (
    SELECT wait_type
        ,wait_time_ms / 1000. AS wait_time_s
        ,100. * wait_time_ms / SUM(wait_time_ms) OVER (
            ) AS pct
        ,ROW_NUMBER() OVER (
            ORDER BY wait_time_ms DESC
            ) AS rn
    FROM sys.dm_os_wait_stats
    WHERE wait_type NOT IN (
            'CLR_SEMAPHORE'
            ,'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'
            ,'CLR_AUTO_EVENT'
            ,'DISPATCHER_QUEUE_SEMAPHORE'
            ,'FT_IFTS_SCHEDULER_IDLE_WAIT'
            ,'XE_DISPATCHER_WAIT'
            ,'XE_DISPATCHER_JOIN'
            )
    )
--Insert into OptimizationFinal.perf.TopWaitsInServer
SELECT W1.wait_type
    ,CAST(W1.wait_time_s AS DECIMAL(12, 2)) AS wait_time_s
    ,CAST(W1.pct AS DECIMAL(12, 2)) AS pct
    ,CAST(SUM(W2.pct) AS DECIMAL(12, 2)) AS running_pct 
    --Into TopWaitsInServer
FROM Waits AS W1
INNER JOIN Waits AS W2 ON W2.rn <= W1.rn
GROUP BY W1.rn
    ,W1.wait_type
    ,W1.wait_time_s
    ,W1.pct
HAVING SUM(W2.pct) - W1.pct < 80;-- percentage threshold

SQL Script Output Screenshot

User Level to execute

300

Hope you will like How to Identify Top Nth waits With I / O Specification.

If you really like reading my blog and understood at least few thing then please don’t forget to subscribe my blog.

If you want daily link and analysis or interesting link go to following website which will give @ your inbox please subscribe our following link resource blog :

Link Resource Website

For More information related to BI World visit my Mentalist Blog

SQL Server Mentalist >> SQL Learning Blog

Business Intelligence Mentalist >> BI World

Infographic Mentalist >> Image worth explaining thousand Words

Microsoft Mentalist >> MVC,ASP.NET, WCF & LinQ

DBA Mentalist >>Advance SQL Server Blog

Microsoft BI Mentalist >> MS BI Development Update

Connect With me on

| FaceBook |Twitter | linkedIn| Google+ | WordPress | RSS |