Skip to main content
cancel
Showing results for 
Search instead for 
Did you mean: 

Enhance your career with this limited time 50% discount on Fabric and Power BI exams. Ends August 31st. Request your voucher.

Reply
Anonymous
Not applicable

Inconsistent CSV Dataflow Refresh Times

Hi Everyone,

 

I have a simple dataflow (Premium workspace) that connects to multiple csv/excel files in a sharepoint folder on an hourly refresh schedule. I have noticed that the refresh times vary from 1 min to 7 hours! Does anyone know what could be causing this?

 

I notice the long refresh times tend to happen between 6AM to 12PM Australian Eastern Standard Time (AEST). I am not performing any complex transformations such as merging or grouping. Only pulling data from the csv file and changing column types.

 

1 of the CSV files is quite large (~1.2M rows, 400MB) , I am trying to implement an incremental refresh policy on this table

 

Any help on this would be much appreciated!

 

PatrickK95_1-1656990978139.png

 

PatrickK95_2-1656991139871.png

 

 

 

2 REPLIES 2
v-cazheng-msft
Community Support
Community Support

Hi @Anonymous ,

 

From the screenshot, we can see that refresh duration is not too long, but their wait time is a little bit long. So during the refresh, too much time is costed on waiting for the resource such as memory to handle the refresh.

vcazhengmsft_0-1657193295051.png

 

May I know how many datasets in your Premium workspace? Is there any other scheduled refresh adjacent to the scheduled refresh time of current dataset? If you move this dataset to a new Premium capacity and refresh there, will you see the refresh duration be long?

 

Best Regards,

Community Support Team _ Caiyun

Anonymous
Not applicable

Hi Caiyun,

 

Thanks for responding.

 

There are only 6 other dataflows in the workspace (No datasets). None of these dataflows share a scheduled refresh during the problematic time period (6AM-12PM). Although there is 1 dataflow that refreshes roughly at 5AM. I have copied the dataflow to a seperate, empty premium workspace and there is no difference in refresh performace. 

 

Is there any way to narrow down what is costing the memory resource?

 

PatrickK95_0-1657250001471.png

 

Helpful resources

Announcements
August Power BI Update Carousel

Power BI Monthly Update - August 2025

Check out the August 2025 Power BI update to learn about new features.

August 2025 community update carousel

Fabric Community Update - August 2025

Find out what's new and trending in the Fabric community.