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Nima Mohandesan's avatar
Nima Mohandesan
Copper Contributor
Dec 02, 2019

Data modelling, SQL JOIN vs. Power Query join

Hi,

I wonder what is the best practice when it comes to querying for data into a data model. There are times that we can use SQL JOIN to pull data directly into Power Query, but also we can achieve this by bringing in table data and then establish connection in the data model (fact and lookup). I am not sure what method is preferred in general. Thank you. 

BI & Data Analysis
excel
power bi

2 Replies

  • Wyn Hopkins's avatar
    Wyn Hopkins
    MVP
    Dec 02, 2019

    Hi Nima Mohandesan 

     

    Fact and lookup is normally the best way to go.  The narrower your tables are the better (faster calculation) so flattening them by merging is not advised for Fact Tables

     

    Lookup tables however should be flattened to result in a Star Schema.  This again has better performance and is easier to use than a snowflake schema

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