Calculated members

Calculated members add business logic into dimensions by introducing members whose value is computed from the values present within the underlying data.

The new members are available for use without being added to the underlying relational data source. A calculated member is defined by a dimensional expression.

A calculated measure is a calculated member that belongs to the measure dimension. There are no behavior differences between calculated members and calculated measures.

For more information, see Calculated members in reports.

For information about relative time calculated members, see Model relative time dimensions.

Table 1. Properties of a calculated member
Property Description
Name The name that appears in the IBM Cognos studios. If the project supports multiple locales, there can be versions of the name in all supported languages.
Parent Member

Specifies the parent of the calculated member in the member tree.
Expression

Defines the value of the calculated member using other members and a valid set of multidimensional operators and functions.

Table 2. Properties of a calculated measure
Property Description
Name The name that appears in the IBM Cognos studios. If the project supports multiple locales, there can be versions of the name in all supported languages.
Expression

Defines the value of the calculated measure using other members and a valid set of multidimensional operators and functions.
Data Format

Set the default data properties for each type of data.

Visible

Controls whether the object is visible in the published package.

Non-visible measures are typically used to represent intermediate values in the construction of a complex calculated measure. These measures are not intended to be used for direct reporting. However, a non-visible measure is always present in the published package because the measure might be needed by other objects in a dynamic cube.

Non-visible measures are not displayed in the metadata browser and are removed from the output of reports which contain references to them. For example, a report that references a non-visible measure does not include output from that measure.

Default: True

Regular Aggregate

The primary method used to aggregate data for the measure.

Default: Sum

Author calculated member expressions

IBM Cognos Cube Designer validates the syntax of expressions. After a cube is started, the dynamic cube engine validates the semantics of the calculated member and calculated measure expressions. Any calculated member or expression which is not successfully validated during cube start is removed from the cube and is not available in the studios.

The expression editor does not limit functions to the valid ones for a specific context.

There are some restrictions that apply to IBM Cognos Dynamic Cubes calculated members.

Do not use the following relational constructs in expressions used to define calculated members:

  • Value summary functions (Not Member Summary functions)
  • Value Analytic functions (rank, first, last, percentile, percentage, quantile, quartile, distinct clause, prefilter clause) - (Summaries/Member Summaries)
  • Value Summary functions (standard-deviation-pop, variance-pop, distinct clause, prefilter clause)
  • All running- or moving- summary functions (Summaries)
  • All FOR clauses in aggregate functions (Summaries/Member Summaries)
  • Date/time constants (Constants)
  • All business date/time functions (Business Date/Time functions)
  • Like, lookup, string concat '||', trim, coalesce, cast (Common Functions)
  • MOD function (Common Functions)