Writing
Notes, tutorials and ideas about data analysis and data engineering.
Example post — everything the site can do
A working demo of every feature available when writing a post. Delete this file once you have posts of your own.
Why your Power BI model is slow (and what a star schema fixes)
Most slow reports are not a DAX problem. They are a modelling problem, and the fix is older than Power BI itself.
Window functions, explained without the jargon
Running totals, rankings and "compare each row to its group" — all without a self join.
VLOOKUP, INDEX/MATCH, XLOOKUP — which to actually use
Three ways to do the same job, twenty years apart. Only one is worth learning today.
dbt for people who already know SQL
If you can write a SELECT, you are most of the way there. The rest is file layout and two macros.