Forum Discussion
Assistance Required with Query Performance Issue
where the DAX query runs successfully with SQL Server as the data source. However, when using a data flow as the source, the query exceeds the time limit.Was that SQL Server data source accessed in Direct Query mode? Is the dataflow accessed in import mode?
Hi lbendlin
Thank you for your response.
both the SQL Server and the data flow are accessed in Import mode, not DirectQuery.
In that case the data source shoud not matter as in both scenarios your query is running as a DAX query against the semantic model, and not against the original source in Direct Query mode.
Use DAX Studio to examine the query plan and make adjustments.
Hi lbendlin ,
I’ve encountered a performance issue when running the same DAX query across two different data sources. When I run the query against our SQL data source, it completes in about 393 ms. However, when running the same query against the Data Flow as the data source, it takes significantly longer—around 34 seconds (34,000 ms).I’m unsure why this discrepancy is occurring. Could you please help me understand what might be causing the slower performance when using the Data Flow source? Any guidance or suggestions on how to optimize the query Please Help me.
These results are weird. Can you please show the data model in each case?