Preemptive Wait Types

  • Enrico van de Laar


Unlike SQL Server, the Windows operating system uses preemptive scheduling to schedule and manage threads. Sometimes SQL Server has to use Windows functions to perform specific actions through the operating system, for instance, when checking Active Directory permissions. When this occurs, SQL Server will have to ask a thread from the Windows operating system, outside of SQL Server, thus making it impossible for SQL Server to manage that thread. While SQL Server is waiting for the preemptive thread inside the Windows operating system to complete, SQL Server will record a wait on a preemptive Wait Type.


Window Function Preemptive Schedule Query Window Window Operating System Authentication Request 
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Copyright information

© Enrico van de Laar 2015

Authors and Affiliations

  • Enrico van de Laar
    • 1
  1. 1.De NijverheidDrachtenThe Netherlands

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