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Towards Data Science

A deep dive into how DAX filtering works under the hood, using DAX Studio server timings to analyze query execution. Covers simple filters, FILTER() function behavior, filters inside measures, multiple filters, and complex filters using functions like CONTAINSSTRING(). Key findings: simple filters are pushed to the Storage Engine (SE) as WHERE clauses and are efficient; FILTER() can produce different results and forces more Formula Engine (FE) work with intermediate materialization; the SE can use multiple CPU cores while the FE is single-threaded. Practical guidance is given on minimizing FE workload, reducing SE query count, and avoiding unnecessary use of FILTER().

Take a Deep Dive into Filtering in DAX