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Advocate I
Advocate I

Very long refresh-/loading-times with MySQL database



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 ( --> no change


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

Advocate I
Advocate I

push Smiley Frustrated


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?



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.

Regular Visitor

Hi  @jlie,


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

Regular Visitor

have got any improvements till now?

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