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

Calling all Data Engineers! Fabric Data Engineer (Exam DP-700) live sessions are back! Starting October 16th. Sign up.

Reply
jlie
Advocate I
Advocate I

Very long refresh-/loading-times with MySQL database

Hey,

 

PowerBI seems to be getting very slow when updating/refreshing data from our MySQL Server. When I hit the refresh, PowerBI is taking ages (several minutes!) in "Evaluating..." step.

 

Here are some information about my queries and the environment that might help to understand:

  • The server is powerfull enough and could easily handle the load
  • The source-tables are fairly small, most of them have around 4k rows, some 500k. Nothing spectecular
  • the queries are all very well folded, I rarely end up importing more than 10k rows
  • when the quries are finally executed, the load is done in a couple of seconds
  • Other sources (Salesforce, Google Analytics, local files) do not have the problem (Evaluation is very short)
  • the problem occurs with the regular refresh from the Datamodel and when refreshing previews in Query Editor

 

What did I already try?

  • updated to latest version of PowerBI Desktop --> did not improve performance
  • updated to latest version of MySQL Connector / Driver (originally was the version PowerBI recommends) --> no change
  • re-installing, clearing cache of PowerBI Desktop --> no change
  • simplifying the queries --> small improvement, but still taking ages; even if I import a raw table (e.g. just a SELECT * FROM abc statement) with no M-Steps at all, "Evaluating" takes very long
  • disabling auto date/time (https://community.powerbi.com/t5/Desktop/Power-BI-Desktop-Refresh-Slow/td-p/22336) --> no change

 

Does anybody has any idea what could cause the problem? Anything is appreciated!

5 REPLIES 5
Miles_
Regular Visitor

have got any improvements till now?

nfiorilla
Regular Visitor

Hi  @jlie,

 

Could you resolve this problem? I have the same problem with my MySQL engine.

v-ljerr-msft
Microsoft Employee
Microsoft Employee

Hi @jlie,

 

You've tried almost everything I can think of.Smiley LOL Just one more check, could there be too much columns in your tables? If that is case, could you try removing the unused fields/columns to see if it helps? And have you tried importing the same data with Excel to see how long it takes for refresh?

 

Regards

Hey @v-ljerr-msft, unfortunately, the columns can not be the problem's cause. I already tested it with just one single ID column and had no improvement in "Evaluating" at all.

 

Importing the data from files is not exactly possible, since my original queries have some advanced stuff like joins, complex filters, etc. However, importing CSV/Excels in general works flawlessly, so I guess that would not help me either.

jlie
Advocate I
Advocate I

push Smiley Frustrated

Helpful resources

Announcements
FabCon Global Hackathon Carousel

FabCon Global Hackathon

Join the Fabric FabCon Global Hackathon—running virtually through Nov 3. Open to all skill levels. $10,000 in prizes!

October Power BI Update Carousel

Power BI Monthly Update - October 2025

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

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.