Forum Discussion
Data Load Issue using Multiple tables append and Multiple left merge queries
Hi Nisha_Goyal,
Please try using a Power BI Dataflow in the service to perform your merges and appends this can help offload the heavy processing from Power BI Desktop and may resolve the memory allocation issue.
Memory error: Memory Allocation failure. Try simpl... - Microsoft Fabric Community
Solved: Memory error: Memory Allocation failure on Power b... - Microsoft Fabric Community
Thank you.
Hi Nisha_Goyal
Power BI’s ETL engine (Power Query) isn’t optimized for heavy transformations or large multi-source merges. It loads all intermediate results into memory, which can easily cause memory allocation failures when combining tables from different sources such as Azure Databricks and SharePoint.
Recommended approach:
Perform all heavy joins, merges, and appends before Power BI — directly in Databricks, SQL Server, or another database.
Keep Power BI for lightweight transformations only (renaming, filtering, formatting).
If pre-processing isn’t possible, try breaking queries into smaller parts, disabling query load for intermediate steps, and using staging tables or Dataflows.
If this post helps, then please consider Accepting it as the solution to help the other members find it more quickly