Join us at FabCon Atlanta from March 16 - 20, 2026, for the ultimate Fabric, Power BI, AI and SQL community-led event. Save $200 with code FABCOMM.
Register now!Join the Fabric FabCon Global Hackathon—running virtually through Nov 3. Open to all skill levels. $10,000 in prizes! Register now.
I am using Premium Per User licence, Added a new DataMart in a Premium Workspace with a Postgres connector.
The data has aprox 3 million rows , Caching is turned on but itis very slow to load the Transform function to build joins to a second datamart. Is there any way to make this faster. Taking aprox 15 to 20 mins to load every time I select transform.
The patterns I'd go in most cases, depending on whether I want to use Import, are:
- Dataflow(s) > Datamart > SQL endpoint > Import (or composite) dataset > reports
- Dataflow(s) > Datamart > auto-generated DQ dataset > reports
This is based on my current understanding of datamarts, I reserve the right to change my mind!
In their present state it is completely impractical to do any ETL within the datamart, you want to do all your transformations in upstream dataflows.
It sounds like i am using this Datamart incorectly, it automaticly created a Dataset with the same name.
Are you saying I should create a Dataflow and connect to the autocreated dataset, do all the ETL there and point my report to the Dataflow?
I guess I dont get the advantage?
Hi @nrowey
Yeah this is expected to happen because it has to first load all the data before it can do the join. So each time this happens it has to load the data to then find the joins.
The only way to do this faster is to do the joins in the PostGres database query?
Join the Fabric FabCon Global Hackathon—running virtually through Nov 3. Open to all skill levels. $10,000 in prizes!
Check out the September 2025 Power BI update to learn about new features.