Custom Rollup Operators
Custom rollup operators provide a simple way to control how level member values are rolled up to their parent's values. When custom rollup operators are assigned a column, either when creating them as an optional feature of new parent-child dimensions in Dimension Wizard or adding them to existing dimensions in Dimension Editor or Cube Editor, the contents of that column are used as the custom rollup operator for each member. This custom rollup operator is applied to the member when evaluating the value of the member's parents.
In Dimension Editor, custom rollup operators are enabled by setting the Unary Operators property of the level to True. Values for the custom rollup operators are stored in the column listed by the Define Unary Operator Column dialog box and are applied to each member.
Custom rollup operators provide similar but simplified functionality of custom member formulas. In comparison to custom member formulas, which use Multidimensional Expressions (MDX) expressions to determine how members are rolled up, the custom rollup operator uses simple math operators to determine how the value of a member affects the parent. Like custom member formulas, the value of the custom rollup operator is unique for each level member.
In terms of precedence, a level's custom rollup operators override the custom rollup expression of the previous level. However, the custom member formulas of the preceding level override the custom rollup operators of a level.
Custom rollup operators can be enabled for both shared and private dimensions. To enable custom rollup operators in a level for a dimension, use its Unary Operators property in the properties pane of Dimension Editor (if the dimension is shared) or Cube Editor (if the dimension is private). Clicking the edit (...) button beside this property's value displays the Define Unary Operator Column dialog box in which you select or create a column to store the formulas. After you close this dialog box, if the shared dimension is a write-enabled, parent-child dimension, you can select values for the UNARY_OPERATOR member property in the custom member formula pane of Dimension Editor or Dimension Browser. (To perform this action, make sure that the write-enabled dimension is included in a cube that was processed since the dimension last changed and process the cube after changes have been made.) If the dimension is not write-enabled, you must use a tool other than Analysis Manager to insert the formulas into the column.
Note If a cube has a measure with its Aggregate Function property set to Distinct Count, adding a custom rollup operator or expression to a level will cause the structure of the cube to become invalid.
See Also
Custom Rollup Formulas and Custom Member Formulas