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

The Power BI Data Visualization World Championships is back! Get ahead of the game and start preparing now! Learn more

Reply
silcambro
Frequent Visitor

Dataflow and Snapshot

Hello,

 

I have a Power BI workspace and I set the Storage to my Azure Data Lake.

 

I created a Datafow and as expeced the Data are saved in my ADLS in CDM format.

 

What is strange, at least for me, is that every time  I refresh the dataflow a new CSV file is created and the previous file

is not overwritten. Essentially a snapshot is created and added to the folder. Is there a way i can limit the number of snapshots created or my ADLS will grow to infinite size.

 

Thank you so much

 

  

4 REPLIES 4
otravers
Community Champion
Community Champion

Azure Data Lake has lifecycle management options:

https://learn.microsoft.com/en-us/azure/storage/blobs/lifecycle-management-overview

------------------------------------------------
1. How to get your question answered quickly - good questions get good answers!
2. Learning how to fish > being spoon-fed without active thinking.
3. Please accept as a solution posts that resolve your questions.
------------------------------------------------
BI Blog: Datamarts | RLS/OLS | Dev Tools | Languages | Aggregations | XMLA/APIs | Field Parameters | Custom Visuals
nqzhhzmn
Advocate II
Advocate II

This is by design so Microsoft can sell more storage space.  There is no way to limit the space usage.

silcambro
Frequent Visitor

Hello,

 

thank you so much for your reply.

 

My source are CSV files in Azure Data Lake.

 

And as you Know when Data flow Runs it will generate a CDM Folder,

those are the file in one of the CDM Snapshot Folders after three refreshes:

 

orderheader.csv@snapshot=2020-12-04T22:07:00.6513096Z

orderheader.csv@snapshot=2020-12-09T18:34:44.7746893Z

orderheader.csv@snapshot=2020-12-24T21:25:08.5191499Z

 

and this is the Image

 

Screenshot 2020-12-24 134054.png

Dataflow Name : Orders

Query: orderheader

 

It is the normal behavior didn't set anything in particular.

 

Any ideas, if this is by design?

 

Thank you so much

 

 

 

 

Anonymous
Not applicable

Hi @silcambro 

Could you tell me what kind of datasource did you use to build your dataflow?

I think your issue may be that when you refresh your dataflow, your file in Azure Data Lake will create a new file instead of overwritting the previous file. 

Does the new file have the same name as the previous one?

Please show me a screenshot of your issue.

You may try to delete the previous, and check whether the dataflow will work well.

The blogs as below may help you.

Blog: Dataflows in Power BI

 

Best Regards,

Rico Zhou

 

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

Helpful resources

Announcements
Power BI DataViz World Championships

Power BI Dataviz World Championships

The Power BI Data Visualization World Championships is back! Get ahead of the game and start preparing now!

December 2025 Power BI Update Carousel

Power BI Monthly Update - December 2025

Check out the December 2025 Power BI Holiday Recap!

FabCon Atlanta 2026 carousel

FabCon Atlanta 2026

Join us at FabCon Atlanta, March 16-20, for the ultimate Fabric, Power BI, AI and SQL community-led event. Save $200 with code FABCOMM.