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dilkushpatel's avatar
dilkushpatel
Icon for Helper III rankHelper III
6 years ago
Solved

Report refresh and calculated column changes takes long time to apply

We have a report which is approx 600 MB big

It has quite a lot of calculated columns and some calculated columns depend on other calculated columns

 

This report was refreshing fine till couple of weeks back but not it takes almost 15 min on working on stage if I make any changes to any calculated columns and sometimes on measures as well

 

if I refresh report there also it takes much longer time even when all rows are loaded, so it takes some 5 min to load all rows and then stays there for another 15-20 minutes

 

How can we improve this?

 

We are in process of migrating all calculated columns to source itself, however initials testings were not that satisfactory.

4 Replies

  • edhans's avatar
    edhans
    Icon for Community Champion rankCommunity Champion

    Convert as many calculated columns to custom columns in Power Query. Depending on your data source, you may get much faster results of the calculations are sent back to a relational database, like SQL.

    Data coming in from Power Query also gets treated as imported data in the DAX model, so it is compressed and needs no additional RAM or CPU to process, as it is pre-processed before it is imported.

     

    Calculated columns should be used sparingly and in specific circumstances. It isn't impossible, but it is rare to get better peformance from them than from custom columns in Power Query.

  • mwegener's avatar
    mwegener
    Icon for Most Valuable Professional rankMost Valuable Professional

    Hi dilkushpatel ,

     

    check this videos...

    VertiPaq Analyzer

    https://www.youtube.com/watch?v=1A7gFFvlRFI

    https://www.youtube.com/watch?v=frTcFzdxHH4

    Debugging a slow Power BI report

    https://www.youtube.com/watch?v=eABg872TAJU

     

    ...and this blog post.

    https://www.sqlgene.com/2019/09/27/a-comprehensive-guide-to-power-bi-performance-tuning/

     

    If I answered your question, please mark my post as solution, this will also help others.

    Please give Kudos for support.

     

  • v-yuta-msft's avatar
    v-yuta-msft
    Icon for Community Support rankCommunity Support

    dilkushpatel ,

     

    Please check if there're any useless DAX formula in your report. Make sure each column will be used, remove the useless columns. For more details about how to improve the query in power bi, I would suggest you refer to doc below:

    https://docs.microsoft.com/en-us/power-bi/power-bi-reports-performance

     

    Community Support Team _ Jimmy Tao

    If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

    • dilkushpatel's avatar
      dilkushpatel
      Icon for Helper III rankHelper III

      We are in process of doing everything mentioned here

      i.e 

      1) remove extra calculated columns which are not used anywhere

      2) move what all we can to data lake analytics