14  Optimize a model for performance in Power BI


Summary

Concept Description
Model Slimming
Reduce Model Size Removing unused columns and tables to lower memory footprint
Column Cardinality High-cardinality columns hurt compression and slow queries
Aggregations Pre-summarised tables that speed up high-grain visuals
Calculation Groups Reusable calculation logic applied across measures
Storage Mode Mixing Import and DirectQuery within a single model
Diagnostic Tooling
Performance Analyzer Built-in tool that times each visual on the report page
Query Diagnostics DAX Studio and tools to inspect storage and formula engines
Best-Practice Patterns Star schemas, integer keys, and avoiding bidirectional filters