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sivarajan21's avatar
sivarajan21
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1 year ago
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Visual and dax level optimization that causes report slowdown

Hi,   I have this visual as attached,that has lot of visual level filters applied.   it has a dax measure called data completeness as below: Data Completeness =   var _total = COUNT('Cal...
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  • Anonymous's avatar
    Anonymous
    1 year ago

    Hello sivarajan21 ,

     

    Thank you for reaching out to Microsoft Fabric Community Forum.

    danextian Thank you for your quick response.

     

    sivarajan21 

    Thanks for the update. You've already done a good job reducing the visual load to around 11K, but the DAX Studio trace still shows a higher cost. Here are a few suggestions to further improve performance:

    1. Your current DAX uses SUMMARIZE, which is heavy on performance. Instead, try creating a new column that combines DBName-Point_Id and Date (like DBName-PointId_Date) and use DISTINCTCOUNT on that. It’s much faster.
    2. Please try to use Pre-Aggregate at Source or Use Aggregation Tables. Use pre aggregated tables as the base for your visual instead of calculating combinations on the fly.
    3. In your Data Completeness measure, you're calculating totals every time the visual renders. If that value doesn’t change often, pre-calculate it and reference it directly.
    4. lastly in model design:
      If it is possible use single-direction relationships ( I tried , after changing to single-direction performance is somehow improved). Avoid calculated columns or keys with extremely high cardinality that Power BI struggles to compress.

     

    If this post helps, then please consider Accepting as solution to help the other members find it more quickly, don't forget to give a "Kudos " – I’d truly appreciate it!

     

    Regards,

    B Manikanteswara Reddy

  • tharunkumarRTK's avatar
    tharunkumarRTK
    1 year ago

    sivarajan21 

    I made one change to your measures and I can see some good improvement

    Before change: 10.5 seconds

    After the change: 6.5 seconds 

     Measures 

      MEASURE 'DAX'[Count of Exisitng Days] = 

SUMX ( VALUES( Data[Date] ),  CALCULATE(SUMX(VALUES(Data[DBName-Point_Id]),1)    ) )



    MEASURE 'DAX'[Count of Possible Days] = COUNTROWS ( Points ) * COUNTROWS ( 'Calendar' )



    MEASURE 'DAX'[Data Completeness] = DIVIDE ( [Count of Exisitng Days], [Count of Possible Days] )

    Please test the results and also the performance.

    Also, I saw multiple bidirectional relationships in your model, please avoid them. Same is the case with calculated tables. Avoid them

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Anonymous's avatar
Anonymous
Not applicable
1 year ago

Hello sivarajan21 ,

 

Thank you for reaching out to Microsoft Fabric Community Forum.

danextian Thank you for your quick response.

 

sivarajan21 

Thanks for the update. You've already done a good job reducing the visual load to around 11K, but the DAX Studio trace still shows a higher cost. Here are a few suggestions to further improve performance:

  1. Your current DAX uses SUMMARIZE, which is heavy on performance. Instead, try creating a new column that combines DBName-Point_Id and Date (like DBName-PointId_Date) and use DISTINCTCOUNT on that. It’s much faster.
  2. Please try to use Pre-Aggregate at Source or Use Aggregation Tables. Use pre aggregated tables as the base for your visual instead of calculating combinations on the fly.
  3. In your Data Completeness measure, you're calculating totals every time the visual renders. If that value doesn’t change often, pre-calculate it and reference it directly.
  4. lastly in model design:
    If it is possible use single-direction relationships ( I tried , after changing to single-direction performance is somehow improved). Avoid calculated columns or keys with extremely high cardinality that Power BI struggles to compress.

 

If this post helps, then please consider Accepting as solution to help the other members find it more quickly, don't forget to give a "Kudos " – I’d truly appreciate it!

 

Regards,

B Manikanteswara Reddy

Anonymous's avatar
Anonymous
Not applicable
1 year ago

Hi sivarajan21 ,

 

We wanted to kindly follow up to check if the solution provided for the issue worked? or Let us know if you need any further assistance?

 

If our response addressed, please mark it as Accept as solution and click Yes if you found it helpful.

Please don't forget to give a "Kudos " – I’d truly appreciate it!

 

Regards,

B Manikanteswara Reddy