DAX, or Data Analysis Expressions, is a formula language used in Excel,Power BI, and other Microsoft tools for business analytics and data modeling.

DAX is designed to work with tabular data models, particularly in the context of Power Pivot and Power BI, where it is used to create custom calculations, manipulate data, and build advanced formulas.

• Formula Language:

  • DAX provides a formula language that allows users to create custom formulas for data analysis. Formulas in DAX can perform a wide range of calculations, aggregations, and manipulations on data.

• Tabular Data Models:

  • AX is primarily used with tabular data models, where data is organized in tables with rows and columns. This is common in tools like Power Pivot and Power BI.

• Measures and Calculated Columns:

  • DAX supports the creation of measures and calculated columns. Measures are used for aggregations (sums, averages, etc.), while calculated columns allow the creation of new data based on existing columns.

• Relationships:

  • DAX relies on relationships between tables in a data model. Understanding and defining relationships between tables is crucial for accurate data analysis and calculation in DAX.

• Contextual Calculations:

  • DAX formulas operate in either a row context or a filter context, depending on whether the formula is being evaluated for a single row or within the context of a larger dataset.

• Time Intelligence Functions:

  • DAX includes specialized functions for working with time-based data, allowing users to perform calculations based on dates and time periods easily.

• Aggregation and Filtering:

  • DAX enables users to create powerful aggregations and filters on data, allowing for sophisticated analysis and reporting.