Overview of Levels
A level enables you to group the data, and a level has members.
A member selects a set of records from the cube. For the City level, the Juniper member selects the patients whose home city is Juniper. Conversely, a record in the cube belongs to one or more members.
Possible Member Overlap
The members of a level can overlap each other. That is, a given record can belong to more than one member; this occurs if the level is based on a list. For example, consider the Allergies level, which contains one member for each allergy. A patient can have multiple allergies and thus can belong to multiple members of this level.
Null Values and Null Members
A level can have a Null member; this member selects the records that have no value for the data used by this level. Typically the name of this member is None.
