When some data (or characteristics) aren’t acceptable for storing in the schema, they might be placed in a trash dimension. The data in the trash dimension is generally in the form of Boolean or flag values.
By combining a number of tiny dimensions, a single dimension is created. This is referred to as a “garbage dimension.” The characteristics of the Junk dimension are unrelated. Junk dimension is the technique of gathering random flags and text characteristics in a dimension by transferring them to a distinct sub-dimension.