DAX in 20 Minutes - The Hard Parts
summary
Rapid tour of DAX focuses on why Excel/SQL habits break: DAX uses a columnar VertiPaq engine with value/dictionary/run‑length encoding and routinely delivers 5–10x compression on cleaned analytic tables. DateAdd and similar functions operate over columns and change evaluation, so common Excel patterns return blanks. Debug strategy centers on row context vs filter context and using iterators (SUMX, FILTER) plus CALCULATE to deliberately shift filters and get correct time‑shifted measures.
AI-written summary · about
chapters (9)
- 0:00Introduction to DAX hard parts
- 1:03Why DAX is misleadingly easy
- 2:29DAX as a foreign language
- 4:16DAX shouts in columns
- 6:41Column store optimizations
- 11:15Excel vs DAX date functions
- 13:24Understanding evaluation context
- 16:33Filter vs row context
- 17:38Summary of DAX challenges
related talks
50mDAX Visual Calculations: What You Need to Know
52mThe Fundamentals of DAX Contexts
51mOptimising DAX fusion - Power BI
51mTroubleshooting Power BI Report Performance
58mProductivity Revolution in Excel
01h 05mDynamic Presentation Using Excel CUBE Formulas
54mData Visualization with Power View and the Tabular Model
51mAggregations in Power BI