Data types and encoding
The Power BI model works with a limited number of data types. Choosing the right data type for your data is important, as it determines the way your data is stored, or encoded, and how efficiently the model can process your data. Below is a list of all the data types recognized by Power BI:
- Text: The most generic data type is Text. Virtually all data can be stored as Text. When loading data through Power Query, the generic Power Query data type Any is converted to Text in the Power BI model. This causes numerical columns to be stored as Text when you forget to explicitly make the type conversion in Power Query. (You can, of course, change the data type in the model, which will automatically add a type change step in Power Query.)
- Whole Number: The data type Whole Number is used, as you would guess, to store whole numbers. Because of the way the Power BI model stores and compresses data, this is one of the most efficient data types available...