The core principle described is **value coalescing**, a mechanism within the DAX (Data Analysis Expressions) language and Power BI domain that evaluates expressions sequentially from left to right until it returns a scalar value or determines if no valid candidate exists. Formally defined as returning the first argument that does not evaluate to `BLANK`, this function operates under the condition of strict linear progression where any non-blank result immediately terminates evaluation, ensuring efficient aggregation and data type standardization by substituting nulls with default scalars (e.g., zero). This concept relates directly to database query optimization and handling missing data in measure design, serving as a performance-optimized alternative to nested conditional logic for resolving blank values across filter contexts.
The core principle described is **value coalescing**, a mechanism within the DAX (Data Analysis Expressions) language and Power BI domain that evaluates expressions sequentially from left to right un…