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robarivas's avatar
robarivas
Post Patron
6 years ago
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Efficiently create junk dimensions in power query

I have a large fact table (many millions of rows). It has a bunch of columns in it that I'd like to break out into a few junk dimension tables. However, I have no keys to work with so I was planning ...
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  • ImkeF's avatar
    ImkeF
    6 years ago

    Hi robarivas 

    yes, doing everything on the server-side would probably be the fastest version.

    It's not that PQ cannot do it, but SQL would be faster with it. Just create views for it that you then query.

     

ImkeF's avatar
ImkeF
Community Champion
6 years ago

Hi robarivas 

Multiple levels of merge tend to become slow in PQ. Why not generate some views on the SQL Server already?

Or write them as SQL-queries in PQ.

 

 

  • robarivas's avatar
    robarivas
    Post Patron
    6 years ago

    Thank you ImkeF . Just to clarify: Are you saying I should create the junk dimensions on SQL server? That seems easy and logical. However, wouldn't I still need to merge those tables back to the fact table so that the fact table can obtain the keys. Or are you saying that this step should also be done on the SQL Server side?

    • ImkeF's avatar
      ImkeF
      Community Champion
      6 years ago

      Hi robarivas 

      yes, doing everything on the server-side would probably be the fastest version.

      It's not that PQ cannot do it, but SQL would be faster with it. Just create views for it that you then query.