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vpfaiz's avatar
vpfaiz
Regular Visitor
10 years ago

Star or Snowflake for datamodel?

If I have a snowflake model in my Datawarehouse, do I need to flatten/denormalize that to star schema before connecting Power BI in, to improve performance or storage? I assume that Power BI is using...
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fbrossard's avatar
fbrossard
Icon for Kudo Commander rankKudo Commander
10 years ago

Totally agree with greggyb

 

But with tabular model you can not create a relationship on a "non key" dimension attribute and using a another granularity.

And for this reason, sometimes you have to use snowflake modelisation.

Nowadays, I prefer to use snowflake in my sql dwh and flattenize dimensions by using views.

 

On the other hand, Direct Query would be not so bad in term of performance when combining Clustered Column Store Indexes on your SQL Datawarehouse combining "super dax" querying available in SQL Server 2016:

Just waiting for the SQL Server 2016 RTM and the capability in PBI to create calculated measures when using Direct Query mode (please vote :smileyvery-happy:) https://ideas.powerbi.com/forums/265200-power-bi/suggestions/10435572-create-dax-measures-fields-and-tables-in-direct-q

Anonymous's avatar
Anonymous
Not applicable
10 years ago

fbrossard They released the capability to create measures on direct query in the Desktop update today. Blog

 

  • fbrossard's avatar
    fbrossard
    Icon for Kudo Commander rankKudo Commander
    10 years ago

    Anonymous I know and i've already tweet about that.

     

    From my point of view, it's a major step forward, and we can consider Power BI as an SSAS SaaS solution :)

     

    Just need some another features like :

    - Role for security implementation or the avaibility to use windows authent and propagate the credential till our database and then using the Row Level Security 

    - Translation

    - KPIs