The Part of Data Modelling Everyone Skips (That Breaks Everything Later)
Your measure is right, your data reconciles, and your year-to-date is still wrong - because the model never had a real date table, only a date column pretending to be one.
Data Modeling
// 14 postsPosts about Data Modeling.
Data Modeling posts
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Star Schema Done Right, Part 2: Dimension Tables and Why Cardinality Matters
A dimension table isn't just a lookup. Why fact-to-dimension relationships have to be many-to-one, why bidirectional filtering always causes problems, and how to build dimensions your DAX can trust.
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Star Schema Done Right, Part 1: What a Fact Table Actually Is (And Isn't)
Most introductions to star schema start with the diagram. The star, the centre, the spokes. This one starts with the question: what problem does a fact table solve that a flat table doesn't? Part 1 builds the intuition before the vocabulary, so the rest of the series makes immediate sense.
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How to Say No to a Data Request Without Burning the Relationship
You can't build every dashboard that gets requested. But 'no' lands differently depending on how you say it — and most data people either say yes to everything and resent it, or say no in ways that…
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Your Power BI Report's Performance Problem Is Probably Your Data Model, Not Your DAX
Slow reports get blamed on complex measures. Complex measures get rewritten. And the report is still slow — because the actual problem is a flat table with 47 columns, many-to-many relationships, a…
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Getting Credit for Work That 'Looks Easy'
The more competent you get, the less people see the effort behind what you deliver. A clean dashboard looks effortless. A fast turnaround looks like it was always fast.
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The Difference Between a Dashboard and a Decision Tool (And Why It Matters)
Most dashboards answer the question 'what happened?' Very few answer 'what should we do?' The gap isn't data — it's intent. A dashboard built for the former often actively gets in the way of the la…
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When Your Manager Doesn't Understand What You Built
You delivered a clean model, a solid dashboard, a real solution — and got a blank look in the room. The work was right. But explaining technical work to someone who doesn't share your frame of refe…
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DAX Context Demystified, Part 3: Time Intelligence and Why Your YTD Is Probably Wrong
Time intelligence functions look simple - TOTALYTD, SAMEPERIODLASTYEAR — until they aren't. The reason they break isn't the function. It's that context transition interacts with your date table…
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Avoid Bragging: Talk About Your Work Effectively
Stop cringing. There's a way to talk about your accomplishments in Excel and Power BI that sounds competent, not arrogant. It's all about framing.
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DAX Context Demystified, Part 2: CALCULATE and Context Transition
CALCULATE is the most powerful function in DAX - and the most misunderstood. Once you see how it deliberately replaces the filter context rather than adding to it, every confusing measure result …
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Build a One-Page Executive Dashboard in Power BI That Stakeholders Actually Open
You'll build a clean single-page report: KPI cards, a trend line, and one slicer. The kind that gets opened voluntarily, not just emailed as a screenshot. Starting from a blank canvas, ending with …
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Why 'Just Learn SQL' Is the Wrong Advice for Most Excel Users
The advice is everywhere: if you're serious about data, you need SQL. But for most analysts already working in Excel and Power BI, the gap isn't SQL knowledge - it's data modelling instinct. Here…
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DAX Context Demystified, Part 1: Row Context vs Filter Context
DAX's context confusion cost me hours. Turns out, it's just two simple ideas.