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itchyeyeballs's avatar
itchyeyeballs
Icon for Impactful Individual rankImpactful Individual
4 years ago
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Datamart report slow

Hi All,   I have been playing with the Datamarts feature, has anyone else noticed it's really slow?   I've recreated a portion of an existing dataset as a datamart, (reports against the original ...
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  • GilbertQ's avatar
    GilbertQ
    4 years ago

    Hi itchyeyeballs 

     

    yes this is because the datamart using DirectQuery to the underlying database (SQL Server), while the other report uses the Power BI Vertipaq engine which is super fast.

GilbertQ's avatar
GilbertQ
Icon for Super User rankSuper User
4 years ago

If it has always been slow even when importing I would suggest making sure your dataset is using a star schema. 

 

DirectQuery is as fast as the underlying data source, along with once again a star schema design.

itchyeyeballs's avatar
itchyeyeballs
Icon for Impactful Individual rankImpactful Individual
4 years ago

Hi, we are using a star schema.

 

As a test I lined up two instances of PBI Desktop, one using the original data model and one using the new datamart (both identical in terms of tables, joins and import modes).  I created identical (simple) matrix visuals and tried to expand the same row in each version of the report.

The original data model has an instant reaction every time, the datamart version shows a spinning loading icon for at least 5 seconds (sometimes more)

  • GilbertQ's avatar
    GilbertQ
    Icon for Super User rankSuper User
    4 years ago

    Hi itchyeyeballs 

     

    yes this is because the datamart using DirectQuery to the underlying database (SQL Server), while the other report uses the Power BI Vertipaq engine which is super fast.