PowerBI refresh issue.

[Vasudevan606]

Hi All, 

New to this group, so thank you for the help in advance.   I am currently facing a problem with refreshing the dashboard.   I am using Excel files from a shared drive as input.   Each Excel file is around 20MB in size, but when refreshing, it is displaying in GBs and not completing the refresh even after a day.  

[v-shex-msft · Accepted solution]

Hi @Vasudevan606,

The source file size does not mean the refresh operation only processed with these data, if you query table include complex operations(e.g. merge, combine, reference across query tables , invoke custom functions...), they may also affect the resource that spend on refresh.

Improving Power Query Calculation Performance With List.Buffer() 

Optimising The Performance Of Power Query Merges In Power BI 

I'd like to suggest you take a look at the following document about refresh and improve the performance if this help with your scenario:

Data reduction techniques for Import modeling - Power BI | Microsoft Learn

Regards,

Xiaoxin Sheng