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This wait type is when the indirect checkpoint background process is sleeping between polls to discover a dirty page (i.e. a page in the buffer pool that has been modified). From experimentation, there will be one wait occurring every 100ms, with a duration of 100ms.

(Books Online description: N/A)

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Added in SQL Server version:


Removed in SQL Server version:


Extended Events wait_type value:

The map_key value in sys.dm_xe_map_values is 796 in 2012 and 814 in 2014 RTM. After 2014 RTM, you must check the DMV to get the latest value as some map_key values have changed in later builds.

Other information:

I have not seen this wait type be a noticeable contention point.

This wait type is one that I usually filter out as a benign wait when doing wait statistics analysis.

Known occurrences in SQL Server (list number matches call stack list):

  1. Sleeping for 100ms between polls for dirty pages

Abbreviated call stacks (list number matches known occurrences list):

  1. SOS_Task::PostWait+90