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DAX, or Data Analysis Expressions, is the formula language used in Power BI to create custom calculations. The two principal calculation objects in Power BI are measures and calcul...
CALCULATE is the most important function in DAX because it evaluates an expression in a modified filter context. Its basic syntax is CALCULATE(expression, filter1, filter2, ...), w...
Iterator functions evaluate an expression for each row of a table and then aggregate the results into a single value. Common iterators include SUMX, AVERAGEX, MINX, MAXX, COUNTX, a...
Time intelligence in DAX enables period-over-period analysis using functions such as TOTALYTD, TOTALMTD, TOTALQTD, SAMEPERIODLASTYEAR, DATEADD, PARALLELPERIOD, PREVIOUSMONTH, and t...
The Power BI data model connects tables through relationships, and the structure of these relationships directly affects DAX behavior. Relationships can have cardinality of one-to-...
Power BI offers several storage modes that determine how tables are queried. Import mode loads data into the in-memory VertiPaq engine, providing the fastest performance and full D...