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DMC - Why RUNSTATS performed on IBM_RTMON.ACTIVITY% tables?

  • 1.  DMC - Why RUNSTATS performed on IBM_RTMON.ACTIVITY% tables?

    Posted Fri September 02, 2022 02:26 AM
      |   view attached
    Hello DMC-Team,

    in the utilities event monitor screen I frequently see RUNSTATS utility executions in the monitored database on the IBM_RTMON.ACTIVITY% tables triggered by the DMC application UC_MYMON (see attached file for details). 

    Why does DMC collect statistics on tables that are deleted a few seconds later anyhow?

    Thanks for your feedback in advance.

    Best regards - Matthias

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    Matthias Gärtner-Schür
    DBA
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    #Db2

    Attachment(s)



  • 2.  RE: DMC - Why RUNSTATS performed on IBM_RTMON.ACTIVITY% tables?

    Posted Mon September 19, 2022 10:18 PM
    Edited by System Fri January 20, 2023 04:24 PM
    Hi Matthias,

    Thank you for contacting us. DMC joins three event monitor tables (IBM_RTMON.ACTIVITY%, IBM_RTMON.ACTIVITY_STMT% and IBM_RTMON.ACTIVITY_METRICS%) to retrieve all the events and persist them into the repository. As we want to ensure the Db2 optimizer choose the best access plan to execute the join query, these RUNSTATS commands are executed and statistics information is gathered for the optimizer before the query execution, as suggested by Db2 SME. 

    If you have any concern or requirement, please let us know.

    Best regards,
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    Robbie
    IBM Db2 Data Management Console Team
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    Yuan Gao
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