Improving direct query performance from cube - calculated columns

Hi shuhn1229 ,

Based on your description, the calculated column formula you've provided seems straightforward, yet it's having a significant impact on performance. This can indeed occur with DirectQuery because each interaction with the report prompts new queries to the data source, which can be particularly heavy when involving calculated columns.

1. Sink the calculations to the previous step. If possible, attempt to move the logic of the calculated column to the cube itself, where the calculation can be processed during the cube's processing time rather than at query time.

2. For IF optimization, I usually use <> instead of =.

IF(Table[Task] <> "(blank)",  'Table'[Col2],'Table'[Col1])

I'm guessing this may not be as effective. The probability is that the problem is in the number of iterative calculations required.

3. Use Performance Analyzer: Utilize the Performance Analyzer tool in Power BI Desktop to identify bottlenecks and see which part of your report is causing the delay.
Use Performance Analyzer to examine report element performance in Power BI Desktop - Power BI | Microsoft Learn

4. For further insights, I recommend reviewing the Optimize DirectQuery performance sections in the Power BI documentation.

Best Regards,
Gao
Community Support Team

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