Forum Discussion

gp10's avatar
gp10
Advocate III
2 years ago
Solved

Lakehouse Table Rows Limit

Hi community,
I wanted to ask opinions on how to handle the table row limit of a Fabric Lakehouse.

For a P1 capacity the table row limit is 1.5 bn rows. That is pretty low for a feature that claims to work with big data.

Are there any recommendations on the scenario where our data exceed this limit?

  • If we have a multibillion row table, how to we deal with it?
  • If it is our fact table?
  • If we break it into smaller tables, will we then be able to create DAX measures to calculate metrics that may need data from all these tables? Like a total sum or count?
  • How the performance will be?

 Would love to hear your thoughts.
Thanks.

  • Ok thanks for confirming.  At the moment yes that is a limit as the directlake feature is (attempting to) paging all the rows into the vertipaq engine cache from the lakehouse table.  I don't know whether it is exactly 1.5B rows as there could be a little variance.  However if your Fact table is well above that, then yes it may need splitting if you want DirectLake.

     

    You should be able to use a measure to Sum/Count across multiple tables and it should use directlake

     

     

    You can use Profiler to actually see if a query is using DirectLake or falling back to DQ in your testing.

    Learn how to analyze query processing for Direct Lake datasets - Power BI | Microsoft Learn

4 Replies

  • AndyDDC's avatar
    AndyDDC
    Most Valuable Professional

    Hi gp10, the row limit of 1.5B rows is based on the DirectLake functionality - is this what you are referring to?  The Lakehouse table itself can hold more, it's just that the DirectLake feature will not work with tables > 1.5B rows and will fall back to DirectQuery.

    • gp10's avatar
      gp10
      Advocate III

      Thanks AndyDDC , yes this is what I'm referring to.
      In this case, what options do I have if I want to use Direct Lake with tables more than 1.5b rows?
      Is there a hard limit on the Lakehouse table rows?

      Cheers.

      • AndyDDC's avatar
        AndyDDC
        Most Valuable Professional

        Ok thanks for confirming.  At the moment yes that is a limit as the directlake feature is (attempting to) paging all the rows into the vertipaq engine cache from the lakehouse table.  I don't know whether it is exactly 1.5B rows as there could be a little variance.  However if your Fact table is well above that, then yes it may need splitting if you want DirectLake.

         

        You should be able to use a measure to Sum/Count across multiple tables and it should use directlake

         

         

        You can use Profiler to actually see if a query is using DirectLake or falling back to DQ in your testing.

        Learn how to analyze query processing for Direct Lake datasets - Power BI | Microsoft Learn