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  • Terry , 

    • Once  runstats are cleaned up, how do you determine if rebinds are needed, especially for static programs .  Also on a ongoing basis for when to rebind after the profile is updated, what do you recommend?  
    • Also is anyone using   Autonomic Statistic process via the IBM supplied stored procedures.  How has that been working ? Have their been any caveats in  using the process?
    •  Even when the  stats are updated. How do you determine which db2 packages need to be rebound or be bound?

     This table select * from SYSIBM.SYSTABLES_PROFILES  does contain the PROFILE_UPDATE and PROFILE_USED. Should that drive the rebinds?

    • Will that eventually be in the autonomics statistics flow?
    • I really want to know the good the bad of using this process.
    • In this Catalog Table, there are 2 columns SYSIBM.SYSTABLES_PROFILES, PROFILE_UPDATE , PROFILE_USED, of a profile is updated with a more current date of update, would you want to rebind for everthing reference this Table?
    • Also I was wondering about page sampling versus row sampling, Has the page sampling been successful?
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Special

By Terry Purcell

When DB2 9 for z/OS delivered plan management, the goal was to allow a backup of your static SQL packages such that you could “switch” back to the prior “good” access path if a new REBIND resulted in regression. Although optional in DB2 9, EXTENDED became the default in DB2 10 for z/OS – which allowed an “original” and a “previous” to be stored. The previous would be replaced each REBIND, but the original – that is populated upon first REBIND when plan…

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I recently wrote about the most common mistakes that are made with respect to RUNSTATS collection in DB2 for z/OS. [[LINK: http://destinationz.org/Mainframe-Solution/Systems-Administration/Make-No-Mistake ]] The responses were positive, but looking into this further, I see that these mistakes are being made more frequently…

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The DB2 optimizer exploits the catalog information to choose an access path for a given SQL statement, and RUNSTATS is what populates the catalog. It is important therefore to collect a good base of statistics to give the optimizer a fighting chance of choosing well-performing access paths for your SQL.

Here we will discuss some common mistakes that are made when running RUNSTATS.…

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