Forum Discussion

Anonymous's avatar
Anonymous
Not applicable
8 years ago

Slow data refresh

Hi,

 

Normally my power bi file takes about 5 minutes to refresh, but now it it taking at least 30 minutes (and counting). I noticed that the refresh screen is saying that it has (currently) read several million rows from my source tables which is strange because the source files only have a couple of hundred thousand rows. Does anyone have any idea what the problem may be?

 

Thanks,

 

CM

Need Help

6 Replies

  • Gazzer's avatar
    Gazzer
    Resolver II
    8 years ago

    Is it possible that you have created a full join between two tables? 

    • Anonymous's avatar
      Anonymous
      Not applicable
      8 years ago

      Hi Gazzer I merged a query and expanded one column (i.e. I effectively did a vlookup from one table into another to populate one column). But I don't see why that would cause 20 million rows (and counting) to be read for a table that is only about 115,000 rows?

      • Gazzer's avatar
        Gazzer
        Resolver II
        8 years ago

        What was the join type? 

        Left outer?

        Full outer?

        Something else?

  • Anonymous's avatar
    Anonymous
    Not applicable
    8 years ago

    Any chance you are referencing that table for us in other tables?  I definitely see behavior like this and am the middle of investigating it.  My thought was that the merge was being done each time the table was used which is not what I was expecting when using the initial table as a reference.