DAX functions are categorized based on the problems they solve: Learn DAX basics in Power BI Desktop
: Computed at data refresh and stored in the model; best for filtering or grouping.
: Calculated on the fly based on report filters; more CPU-efficient and generally recommended for most analytical needs. Key Function Categories
: The specific subset of data being calculated (e.g., a specific year or region selected in a report).
Understanding DAX requires more than just memorizing functions; it requires grasping how data is filtered and evaluated:
: Occurs when a formula iterates row-by-row, such as in a calculated column. Measures vs. Columns :
: This is the environment in which a formula is executed.
is a specialized formula language used in Microsoft Power BI , Power Pivot, and Analysis Services to perform custom calculations. While it shares a similar syntax with Excel, DAX is uniquely designed to handle relational data and complex context transitions. Essential Core Concepts