Forum Discussion

Kletzy's avatar
Kletzy
Icon for Advocate III rankAdvocate III
3 years ago

Slow "Evaluating" MySQL - single small table no transformations

We are connecting to a MySQL DB in Azure through a Gateway sitting on a VM (latest version). We are struggling with very slow refreshes which appear to be due to the time taken "Evaluating" these queries (at least on the desktop version). The time has more than doubled since the latest Micrsoft updates.

 

We have tested on a single table in a clean file with 14 rows and 7 columns and zero steps apart from the source and navigation - a very simple clean table with no transformations - and the "Evaluating" still takes 1-2 minutes.

 

Are there any thoughts or suggestions to resolve this?

 

 

Need Help

2 Replies

  • lbendlin's avatar
    lbendlin
    Icon for Super User rankSuper User
    3 years ago

    "Evaluating" means you have modified the meta data sufficiently that Power BI thinks it has to re-fetch it again.  Refrain from making frequent design changes. Do not permit Power BI to probe or infer column types.

     

    Subsequent refreshes (after you endured the "Evaluating" phase ) will run faster - until you make the next larger change.

    • Kletzy's avatar
      Kletzy
      Icon for Advocate III rankAdvocate III
      3 years ago

      Thanks for your reply lbendlin . Strange thing is there were no changes or transformations at all to the table and only 1 table in a clean model as a test. On Sunday 26 Feb - this issue sudddenly went away and refreshes became super fast (down from 2 hours to around 5 minutes) with no changes on our end so Microsoft definitely fixed the issue on their side.