Model parent-child hierarchies

In IBM® Cognos® Cube Designer, you model a parent-child hierarchy when the dimension data is based on a recursive relationship and it is not level-based.

For more information, see Parent-child hierarchies.

To model a parent-child hierarchy, you create attributes, map them to the relational data source and identify which attributes represent the parent key and child key. The child key also acts as the member key.

The top level member in a parent-child hierarchy is determined as the member whose parent is Null.

You define a parent-child hierarchy within a parent-child dimension. Be aware of the following constraints:

A dimension containing a parent-child hierarchy cannot include any other hierarchies.
The attributes used for the parent key and member key cannot be composite keys.
A parent-child hierarchy member cannot contain multiple parents.
If the imported data source contains hierarchy members with multiple parents, you can use surrogate keys in the data source to overcome this issue.

To access the parent-child dimension properties, double-click a parent-child dimension from the Project Explorer tree.

Complete the parent-child dimension definition using the properties listed in the following table:

Table 1. Properties of a parent-child dimension
Property	Description
Name	The dimension name shown in the IBM Cognos studios. If the project supports multiple locales, there can be versions of the name in all supported languages.
Comment	A comment or description of the dimension. Comments are not visible in the IBM Cognos studios.
Default Hierarchy	The parent-child hierarchy defined within the dimension. This property cannot be edited.
Multilingual Support	Disabled (default) - Specifies that members do not have multiple locale support. By Column - Specifies that members support multiple locales. For more information about multiple locales, see Multiple locales.

To access the parent-child hierarchy properties, double-click a parent-child hierarchy from the Project Explorer tree.

Complete the parent-child hierarchy definition using the properties listed in the following table:

Table 2. Properties of a parent-child hierarchy
Property	Description
Name	The parent-child hierarchy name shown in the IBM Cognos studios. If the project supports multiple locales, there can be versions of the name in all supported languages.
Comment	A comment or description of the parent-child hierarchy. Comments are not visible in the IBM Cognos studios.
Default Member	The member value to use when evaluating member expressions, where no value is specified for a hierarchy. If the default member is empty, the root member of the hierarchy is used. To set a default member, drag the required member from the Members folder in the Project Explorer tree.
Root Caption	The caption of the root member shown in the IBM Cognos studios. If the project supports multiple locales, there can be versions of the caption in all supported languages.
Parent-Child	True - Indicates that the hierarchy uses a parent-child structure. This property cannot be edited.
Show Data Members	True (default) - show data members for non-leaf members in the hierarchy. False - hide data members for non-leaf members in the hierarchy. For more information, see Data members.
Caption of Data Members	The caption to use for data members in the hierarchy. Empty (default) - use a Null caption. Parent's caption - use the caption of the parent.

To access properties of an attribute, select the attribute in the Attribute column in the parent-child hierarchy editor. For more information about attribute properties, see Model levels.