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hi_world's avatar
hi_world
Helper III
2 years ago

million-dollar question - Non-Optimal SQL Queries for Many-to-Many Relationships

Hello,  Power BI Direct Query on GCP Views Generates Non-Optimal SQL Queries for Many-to-Many Relationships The problem is that it makes a kind of cross join on NULLs. The following article de...
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hi_world's avatar
hi_world
Helper III
2 years ago

Hi 
Thank you for you response lbendlin 
No, there is no null value in my columns.

There is nothing showing in RI column : 


if you have other ideas I'm interested
Thank you for your help
Best regards

 

lbendlin's avatar
lbendlin
Super User
2 years ago

What's the cardinality of your join columns?

  • hi_world's avatar
    hi_world
    Helper III
    2 years ago

    table1 one to many table2 

    table1 one to many table3 
    This happen when i take fields from table2  and table3 (at the end it's a many to many)

    • lbendlin's avatar
      lbendlin
      Super User
      2 years ago

      what is the cardinallity of the join columns in table1? Anything above 50K is asking for trouble.

      • hi_world's avatar
        hi_world
        Helper III
        2 years ago

        >1 million.
         Do you think there is a workaround?