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MBAKU's avatar
MBAKU
New Member
7 months ago
Solved

SQL Query working on Datamart but not on Fabric Warehouse

I have an SQL query in a powerbi dataflow that is working when it is connected to a datamart. I need to migrate it to a fabric warehouse but when I change the source to the fabric warehouse the previ...
data warehouse
warehouse
  • Thomaslleblanc's avatar
    Thomaslleblanc
    7 months ago

    What you’re seeing (“Evaluation Cancelled” in Dataflow Gen2 when you switch from Datamart to Fabric Warehouse) is usually a mix of:

    1. Power Query Online’s preview/evaluation time limit being hit (10‑minute evaluation window) and/or
    2. T‑SQL differences between Datamart and Warehouse that prevent the query from returning schema quickly enough to validate.
ssrithar's avatar
ssrithar
Icon for Super User rankSuper User
7 months ago

Hi MBAKU ,

 

This is a very common migration issue from Datamart → Fabric Warehouse, and it’s not caused by Dataflow itself.
Your query is valid in Datamart, but Fabric Warehouse has a different SQL engine and execution model, and Dataflow Gen2 is far less forgiving when previewing.Datamarts and Fabric Warehouses do NOT use the same SQL engine, even though both look like “SQL endpoints.

 

So a query that runs in Datamart can:

  • Timeout

  • Fail planning

  • Get canceled
    when evaluated by the Fabric Warehouse engine.

That’s why Dataflow shows:

“Evaluation Cancelled”

This is not a syntax error — it’s an execution/planning failure.

 

Clear next steps for you

  1. Test the SQL directly in the Warehouse endpoint

  2. Identify unsupported constructs

  3. Move complex logic into:

    • Warehouse views, or

    • Precomputed tables

  4. Keep Dataflow Gen2 simple

If this post helps, then please appreciate giving a Kudos or accepting as a Solution to help the other members find it more quickly.
If I misunderstand your needs or you still have problems on it, please feel free to let us know. Thanks a lot!