Member Groups
A member group is a system-generated parent of a collection of consecutive dimension members. Member groups are created in a level that is added immediately above the level that contains the member groups' children. When end users browse a level that contains member groups, they see the names and cell values of the member groups. To end users, member groups look like ordinary members.
A level can contain either member groups or members. It cannot contain both.
Member groups rely on the Order By property of the next lower level. This property specifies the sort order of displayed members. Within this sort order, children of a member group are consecutive.
Member group names are created automatically. A member group name consists of the name of the first child of the member group followed by a hyphen (-) and the name of the last child of the member group.
There are two common uses of member groups. They can be used to provide an intermediate level for drilldown between a level with few members and one with numerous members. To do this, create a copy of the level that contains numerous members immediately above the original, and then create member groups in the new level. You can also use member groups to satisfy the maximum limit of 64,000 members under a single parent member. To do this, create a copy of the level that contains the excess members immediately above the original, and then create member groups in the new level. Each member group contains fewer than 64,000 children. For example, a Client dimension contains only an (All) level and a Client Name level containing 500,000 members. A copy of the Client Name level is created immediately above it and named Client Group. In the Client Group level, member groups are created. Each Client Name member now has a new parent in the Client Group level. If you want to hide the Client Group level, set its Visible property to False.
You can create member groups only in changing dimensions. You cannot create member groups in a dimension's top or bottom level. If this need arises, you can add a level such that the level in which you want to create member groups is no longer the top or bottom level. You can hide the added level by setting its Visible property to False. You cannot create member groups in two consecutive levels of a dimension.
Member groups are not supported for ROLAP dimensions.
To create member groups in a level, set its Grouping property to Automatic in the properties pane of Dimension Editor (if the dimension is shared) or Cube Editor (if the dimension is private).
When you change a level's Grouping property to Automatic, the following properties of the level are affected:
- Member Keys Unique: set to True for lowest level
- Member Names Unique: set to False and read-only
- Order By: set to Name and read-only
- Member Key Column: set to an empty string and read-only
- Member Name Column: set to an empty string and read-only
Also, if the dimension containing the level is a private dimension and its Aggregation Usage property is set to Custom, the Aggregation Usage property of the private dimension is set to Standard.
If the dimension table of a dimension that contains member groups is updated, and the dimension is subsequently processed, a new set of member groups is generated. The names and children of the new member groups are different from the old member groups.