Explaining Lineage in DAX

Lineage in DAX refers to the origin information of data, which is a crucial concept for filtering and data manipulation. The TREATAS function is commonly used to establish lineage, allowing a table of values to act as a filter on a specific column, a technique frequently employed by Power BI's engine. Conversely, lineage can be intentionally cleared by performing a mathematical operation on a variable or using the VALUE function, which then requires filters to be applied explicitly. The examples demonstrate how manipulating lineage affects the behavior of functions like CALCULATETABLE and how measures can be written to either leverage or bypass existing filter contexts.