Forum Discussion
SnowFlake - Direct Query - Slow Perfomrance - Adding Role at Power Query
Why it's slow now
- Adding roles and masking in Snowflake forces full table scans—even unused columns get queried.
- Power BI now unmasks first, filters later, which breaks query folding and slows things down.✅ What to check
On Snowflake side:
- Use column-level masking, not table-level.
- Add clustering keys and materialized views.
- Ensure warehouse is right-sized and optimized.
On Power BI side:
- Maximize query folding in Power Query.
- Use composite models (import + DirectQuery).
- Reduce visuals, optimize DAX, enable Horizontal Fusion.
Why it's slow now
- Adding roles and masking in Snowflake forces full table scans—even unused columns get queried.
- Power BI now unmasks first, filters later, which breaks query folding and slows things down.
✅ What to check
On Snowflake side:
- Use column-level masking, not table-level.
- Add clustering keys and materialized views.
- Ensure warehouse is right-sized and optimized.
On Power BI side:
- Maximize query folding in Power Query.
- Use composite models (import + DirectQuery).
- Reduce visuals, optimize DAX, enable Horizontal Fusion.
Hello, this helped mostly to solve it with Snwoflake team. Thank you for help.