Does Default Summarization has impact on data model optimization

[AM_BSL]

Hi All

Please help me understand the impact of default summarization feature on data model optimization.

If I change all the columns to "Do not Summarize" , will it have any impact on performance? 

Thanks

AM

[v-yangliu-msft]

Hi  @AM_BSL ,

Whether it is "Do not summarize" or "Default summarization" will have an impact on dataset refresh, but the size of the impact is related to the size of the data.

Default Summarization: Although the amount of data on Visual is less, an aggregation operation is required.

Do not summarize: Although there is no aggregation operation, the data on the Visual is fully expanded.

Or you can use dax stadio to see the run time in "Do not Summarize" or "Default Summarization", respectively:

DAX Studio | DAX Studio

To reduce the amount of data refresh time, you can check out the following links to make an optimization for Power BI:

Solved: DAX and Power BI Optimization - Microsoft Power BI Community

Optimization guide for Power BI - Power BI | Microsoft Learn

Power BI Performance Optimization: Make Reports Run Up to 10X Faster (zebrabi.com)

Best Regards,

Liu Yang

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

[AM_BSL]

Hi Liu

We are just creating a dataset for the end user to do the reporting, we are not creating any visuals,
To add to your response, the data volume is huge.
if we simply change the default summarization of all the columns/fields in data model to "Do not summarize" will it impact the performance, will it make the dataset refresh slow?

[FreemanZ]

hi @AM_BSL 

visual value summarization is still visual. Model impact visual, not the other way around.

[AM_BSL]

Hello @FreemanZ  Thanks  for replying on my post. Please elaborate your answer, I could not understand it fully.

We are just creating a dataset for the end user to do the reporting, if I simply change the default summarization of all the columns in data model to "Do not summarize" will it impact the performance, will it make the dataset refresh slow?