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PBI dataflows validating for a VERY LONG TIME!!!


I have a PBI dataflow which connects to Synpase Analytcis (DWH) and files from many SharePoint folders.

Even if I make a small change or add in a new folder, it ends with an error without any details or takes minimum of 1 hour to save the query - The screen basically says - "We are validating the output schemas of your queries to ensure they can be loaded". I changed the underlying content to have only test data so the data flow coding would be fast, still no change AT ALL.

This is frustrating and takes so much time to develop a small piece or make any minor enhancements. In this case my output schema has not changed AT ALL. What is it validating for more than hour?

Status: New
Community Support



That seems to work fine for me. You may take a look at Dataflows best practices.

Resident Rockstar

@v-chuncz-msft - I agree with @Anonymous .  The performance of the Validating Output Schema when saving changes to a Dataflow is too slow.  

Your suggestion to review the Dataflows best practices is not helpful.  The Best practices are targetted at the performance when the Dataflow is refreshed.  There is no correlation between Dataflow refresh and Validation upon save and close.


I can wait up to an hour for the Validation upon saving to finish.  When done, the refresh takes less than 15 secounds.

Not applicable

Same problem here. this is my Friday afternoon save.




Kudo Kingpin

What is going on!
It cannot continue this way.

Hours of work lost

Please fix!

Frequent Visitor

Same here with the slow performance. A mix of mappings from the same source, and no serious transformations (this is our extract dataflow).

Not applicable

I have the same issue. Loading takes 20 minutes....

Resolver I

This is kind of a joke - if I make a modification it spins. If I then take the script out of the dataflow via Advanced Editor and place it into a new dataflow the new query will save in a few seconds.


Would be nice to have some input from Microsoft on this topic. 

Not applicable

It's terrible -  not possible to work. I have limited  access to people which can make for me changes on database. If they do I cannot test it efficiently as process take to long. This is critical point to improve as many people struggling with the same.

Helper I

I agree, small changes take forever in large dataflows, and then after hours you get Validation failed with no reason or clue as to why..... Just a horrible experience.

Advocate II

Same problem here. My dataflow only contains an SQL query without any transformations. It take 2 minutes to refesh, bu forever to validate and save...