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IZ15196: IMPROVE FILTER FACTOR ESTIMATES FOR PREDICATES ON OLAP FUNCTION ROW_NUMBER()

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APAR status

  • Closed as duplicate of another APAR.

Error description

  • This fix will improve filter factor estimates for a predicate
on an olap function, row_number().
.
For example:
.
select *
from (  select t1.*,
               row_number() over (partition by c1, c2, c3) as
rownum
        from t1 ) a
where a.rownum = 1;
.
We would compute better filter factors for the olap function
predicate.

Local fix

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Problem summary


    

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Problem conclusion


    

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Temporary fix


    

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Comments


    

  • Duplicate of IZ15195

    



APAR Information




    

  • APAR number
    IZ15196
    • 

  • Reported component name
    DB2 UDB ESE AIX
    • 

  • Reported component ID
    5765F4100
    • 

  • Reported release
    820
    • 

  • Status
    CLOSED  DUA
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt
    • 

  • Submitted date
    2008-02-08
    • 

  • Closed date
    2009-02-24
    • 

  • Last modified date
    2009-02-24
    • 





    

  • APAR is sysrouted FROM one or more of the following:
    

    • 

  • APAR is sysrouted TO one or more of the following:
    

    
LI73147
    

    • 



Fix information


    



Applicable component levels


    








      
              
                            

              

              [{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSEPGG","label":"Db2 for Linux, UNIX and Windows"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"820","Edition":"","Line of Business":{"code":"LOB10","label":"Data and AI"}}]
              

                          

          
 
        

      

    

      

        

          

            
Document Information


            

            


                        

            Modified date:
            

            24 February 2009
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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