Defining unknown members and Null processing properties

When analysis Services processes a dimension, the attributes in that dimension are populated with all the distinct values in the underlying column of the table or view in the data source view. If analysis Services encounters a null value during processing, by default it converts this Null value to 0 (for numeric columns) or an empty string (for string columns). You can modify the default settings or convert Null values in the extraction, transformation, and loading processes (if any) of the underlying relational data warehouse. In addition, you can enable analysis Services to convert a Null value to a specified value by configuring the following three properties: The unknownmember and unknownmembername properties for the dimension and the The NullProcessing property.

The Dimension Wizard and Cube Wizard enable these properties depending on whether the key attribute of the dimension is nullable or if the root attribute of the snowflake dimension is based on nullable columns. In these cases, the NullProcessing property of the key attribute is set to UnknownMember, and the UnknownMember property is set to Visible.

However, when you generate a snowflake dimension incrementally (that is, the way we work with the Product dimension in this tutorial), or when you use Dimension Designer to define dimensions and then merge these existing dimensions into a cube, you may need to manually set the UnknownMember and The NullProcessing property.

Defining unknown members and Null processing properties

Defining unknown members and Null processing properties