Issue - Power BI Dataflow - Validating Queries - Extremely, Extremely, Extremely Slow

[MartinMason]

I know this is a long running known issue that everyone working with dataflows has just come to accept. I work in Power BI Desktop to do my Power Query development as the Power Query Online experience is, well, miserable. Don't know if it's just our tenant or others are having the same problems. Once development is completed in Power BI Desktop, I copy the query and move to the Power BI dataflow. I can tolerate sitting around waiting for 10-15 minutes for simple changes to validate as that's generally what I've come to expect. However, this week the performance has deterioted to the point where Power BI dataflows are at the point of useless sometimes taking 2 to 3 hours to validate a dataflow with a couple linked entities and some fairly simple transformations. I've switched to just validating schemas instead of the data which helps some but does anyone else have any suggestions?

Once validated, the dataflow refreshes take less than a minute in almost all my cases.

Should have stated that currently we are Premium Per User. But to put in prospective, the query I just changed took over 45 minutes to validate and 11s to refresh. It has 21 tables but the largest one is a little over 1K rows and most are linked entities to other Power BI dataflows....following best practices. No data gateway. No cross source queries. All original sources in the dataflow are linked entities.

[AndyCandy]

Any update on this topic.  I've noticed a severe degredation in the performance of dataflows "Validating Queries" recently - No real changes to anything locally that I'm aware of.

[v-zhangti]

Hi, @MartinMason 

Question 1:

Which kind of data sources does the dataflow get data from? Is there any specific features made to the entity, eg: Merge/Append queries? 

Question 2:

There are a few known limitations to using Enterprise Gateways and dataflows:

• Each dataflow may use only one gateway. As such, all queries should be configured using the same gateway.
• Changing the gateway impact the entire dataflow.
• If several gateways are needed, the best practice is to build several dataflows (one for each gateway) and use the compute or entity reference capabilities to unify the data.
• Dataflows are only supported using enterprise gateways. Personal gateways will not be available for selection in the drop down lists and settings screens.

So it requires to assign an administator role of the gateway to others once you want them to add entities to the dataflow.

Here is the reference.

https://docs.microsoft.com/en-us/power-bi/service-dataflows-on-premises-gateways

If you still have this issue for Power BI, you'd better create a support ticket in Power BI Support , Scroll down and click "CREATE SUPPORT TICKET" to get further help.

Best Regards,

Community Support Team _Charlotte

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

[MartinMason]

Not really what I was asking. Haven't replied until now as I thought the performance issues being experienced last week may have been incurred by the February 2022 release. Performance from 2/19 through 2/22 was pretty decent but today it's back to being "acceptable". Performance difference in "Validating Queries" for the same dataflow was typically 3 minutes on Monday but the same flow is now back to 30 minutes today. Still better than the 2 hours it was taking to validate queries last week.