Season 2

Namaste Power BI

Episode 23

Performance Optimization

⏱ 50:00

Episode Summary

Why reports run slow and how to fix them — VertiPaq compression, cardinality reduction, aggregation tables, query plans, and the Performance Analyzer deep dive.

This is Episode 23 of the free Namaste Power BI course on DevWithData — covering performance optimization. Watch the video above, then pass the MCQ checkpoint to unlock the next episode and update your Data Readiness Index score.

Key Takeaways

→High cardinality columns are the #1 cause of slow reports
→Reduce cardinality: remove unnecessary columns, bin continuous values
→Aggregation tables serve summary queries without hitting detail data
→Performance Analyzer shows DAX query time vs visual rendering time

⚠ Common Interview Pitfalls

•Adding indexes (Power BI doesn't use traditional indexes)
•Using too many calculated columns instead of measures
•Not using Performance Analyzer before guessing at optimizations

Official Reference

Deepen your understanding with official Microsoft documentation.

PL-300 Official Training Course

Microsoft's official instructor-led training for the Power BI Data Analyst certification.

https://learn.microsoft.com/en-us/training/courses/pl-300t00

Power BI Documentation

Complete reference for Power BI Desktop, Power BI Service, and Power BI Embedded.

https://learn.microsoft.com/en-us/power-bi/

Content on DevWithData is original and inspired by official Microsoft resources. The links above point directly to Microsoft Learn — always the authoritative source.

← Ep 22: Calculation Groups

Ep 24: Data Storytelling & Design →

Episode Checkpoint

Sign in to attempt the quiz and unlock the next episode.