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DAX for waiting-list KPIs
DAX patterns for referral-to-treatment reporting, including snapshot and event facts, semi-additive measures, percentage within 18 weeks, median and 92nd percentile waits, and week-on-week comparisons that stay right under any filter.
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TMDL and version control for Power BI semantic models
What TMDL is, how it relates to PBIP and TMSL, what tables, measures and relationships look like as text, and how to review semantic model changes in a Git pull request.
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Power BI performance starts with VertiPaq
How the VertiPaq engine stores an import model, why cardinality drives size and speed, how to split date-time columns and cut unused ones, and how to use Performance Analyzer, DAX Studio and VertiPaq Analyzer to find the real bottleneck.
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Time intelligence for NHS financial years and rolling periods
A date table that works, financial-year-to-date with an April start, rolling 12 months, same period last year, week-aligned comparisons, incomplete months, and calculation groups to stop the measure count exploding.
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A star schema for hospital activity
How I'd design a Power BI star schema for admissions, outpatients and waiting lists, from grain decisions and conformed dimensions to role-playing dates, relationship direction and semi-additive snapshots.
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CALCULATE and filter context, worked through a waiting list
Row context, filter context, what CALCULATE actually does, KEEPFILTERS, REMOVEFILTERS and ALLEXCEPT, and the iterator mistakes that cost time and give wrong answers, each with a worked example.
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Row-level security for shared models
Static and dynamic roles, USERPRINCIPALNAME with a security table, roles in TMDL, testing with View as, performance, and what row-level security doesn't protect, checked against Microsoft's documentation.
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Calculation groups in practice
What calculation groups solve, how SELECTEDMEASURE and its sibling functions work, precedence, dynamic format strings, the implicit measures setting, field parameters, and the pitfalls, with TMDL from my theatre utilisation model.