Dan English gave a presentation on optimizing Power BI and Analysis Services Tabular data models for performance. He discussed required tools like DAX Studio, Vertipaq Analyzer and Tabular Editor. Key steps included reviewing table and column sizes, DAX expressions, and best practices like star schema design and simplifying calculations. Resources on optimization best practices and troubleshooting performance were provided.

1. PASSMN – Data Saturday #13 – Oct 16, 2021
Power BI / AAS data
model optimization 101
Dan English

2. Speaker
Background
Dan English
Cloud Solution Architect
Microsoft
http://denglishbi.wordpress.com
@denglishbi
• Published Author / Contributing
Editor

3. Agenda
• Required Tools
• Steps / Process
• Model Review
• Best Practices
• Resources
• Questions

4. Required Tools
• DAX Studio
• Vertipaq Analyzer
• Tabular Editor
• Best Practice Analyzer
• Performance Analyzer (Power BI
Desktop)

5. Initial Step – get metrics & review
DAX Studio
• Connect to data model
• Export metrics (vpax file)
Vertipaq Analyzer
• Open vpax file
• Review tables, columns, DAX
expressions

6. Key items for Review
• Table sizes (typically target large ‘Fact’ tables)
• Column sizes, cardinality, and data types
• IsAvailableInMDX
• Chris Webb's BI Blog: How The New IsAvailableInMDX Property For Analysis Services Tabular
Can Reduce Memory Usage And Speed Up Processing
• DAX Expressions
• Calculated columns
• DISTINCTCOUNT
• Analyzing the performance of DISTINCTCOUNT in DAX - SQLBI
• Basic math and division (use DIVIDE)
• Multiple measure references in a measure (use variables)
• Optimizing IF conditions by using variables - SQLBI
• Avoid using FILTER as a filter argument in DAX - DAX | Microsoft
Docs
• Evaluate which columns are not referenced in DAX or
used in relationships (in Fact table)

7. Best
Practices
Star Schema design
Only include what is needed for reporting / analysis
Perform logic / calculations upstream to source as much as possible
Only load granularity needed for reporting
Watch out for precision and type of data
Auto Date/Time (enabled by default in Power BI)
Reduce / simplify reporting
Naming convention and DAX model references

8. Downloads
• DAX Studio *
• Vertipaq Analyzer
• Tabular Editor *
• Business Ops Installer (External Tools installer)
• One Tool to Install them ALL - (powerbi.tips)
* portable zip version available

9. Resources
• My CHECKLIST for troubleshooting Power BI Performance - YouTube
• Understand star schema and the importance for Power BI - Power BI |
Microsoft Docs
• Data models within Azure Analysis Services and Power BI | Azure Blog
and Updates | Microsoft Azure
• Best Practice Analyzer for Tabular Editor Update 5/20
• best practices | Search Results | (desertislesql.com) (3 part series)
• 10 Best practice tips to improve your Tabular Model performance |
BI4ALL - Turning Data Into Insights
• (11) Guy in a Cube - YouTube (best practice search)
• Improve Power BI Performance by Optimizing DAX | MAQ Software

10. Questions