About Calculated Measures

Calculated measures return values that are computed at run time from data stored in one or more measures. Like relational views, calculated measures store queries against data stored in other objects. Because calculated measures do not store data, you can create dozens of them without increasing the size of the database. You can use them as the basis for defining other calculated measures, which adds depth to the types of calculations you can create.

Because calculated measures do not contain data, they are not associated with a build process. You can create a calculated measure at any time, and it is available immediately for querying by SQL applications.

Table: OLAP Calculation Types lists the predefined calculations and provides links to specific information about defining each type.

Table 6-3 OLAP Calculation Types

Category	Calculation	Description
Share	Share	Calculates the ratio of a measure's value for the current dimension member to the value of a selected member.
Rank	Rank	Orders the members of a dimension based on the values of the selected measure.
Prior and Future Periods	Prior Period	Returns the value from an earlier time period.
Prior and Future Periods	Difference from Prior Period	Calculates the difference between the values of the current time period and an earlier time period.
Prior and Future Periods	Percent Difference from Prior Period	Calculates the percent difference between the values of the current time period and an earlier time period.
Prior and Future Periods	Future Period	Returns the value from a later time period.
Prior and Future Periods	Difference from Future Period	Calculates the difference between the values of the current time period and a later time period.
Prior and Future Periods	Percent Difference from Future Period	Calculates the percent difference between the values of the current time period and a later time period.
Period to Date	Period to Date	Uses the selected aggregation method to calculate the values within a range up to the current time period.
Period to Date	Period to Date Period Ago	Uses the selected aggregation method to calculate the values within a range up to a prior time period.
Period to Date	Difference from Period To Date Period Ago	Uses the selected aggregation method to calculate the difference in values within a range up to the current time period compared to the same calculation up to a prior period.
Period to Date	Percent Difference from Period To Date Period Ago	Uses the selected aggregation method to calculate the percent difference in values within a range up to the current time period compared to the same calculation up to a prior period.
Parallel Period	Parallel Period	Returns the value from a parallel period.
Parallel Period	Difference from Parallel Period	Calculates the difference in values between the current time period and a parallel period.
Parallel Period	Percent Difference from Parallel Period	Calculates the percent difference in values between the current time period and a parallel period.
Moving Aggregates	Moving Total	Calculates the total over a rolling number of time periods.
Moving Aggregates	Moving Average	Calculates the average over a rolling number of time periods.
Moving Aggregates	Moving Maximum	Returns the maximum value over a rolling number of time periods.
Moving Aggregates	Moving Minimum	Returns the minimum value over a rolling number of time periods.
Percent Difference	Percent Difference Between Two Measures	Calculates the percent difference between the values of two measures.
Averages	Average of Two Measures	Returns the average of two measures.
Averages	Average of Three Measures	Returns the average of three measures.
Hierarchy Members	Ancestor at Level (Text)	Returns the ancestor of the current dimension member at a specified level in the dimension hierarchy.
Hierarchy Members	Child Count	Returns the number of children of each member of the specified dimension hierarchy.
Hierarchy Members	Hierarchy Depth	Returns the depth of each member in the specified dimension hierarchy.
Hierarchy Members	Hierarchy Level (Text)	Returns the level of each member in the specified dimension hierarchy.
Hierarchy Members	Hierarchy Parent (Text)	Returns the parent of each member of the specified dimension hierarchy.
Hierarchy Members	Hierarchy Top (Text)	Returns the top value in the specified hierarchy.
Measure with QDR	Measure with QDR	Limits the values of a measure to those for the single dimension members specified by the qualified data reference (QDR).
OLAP DML Expression	OLAP DML Expression	Returns the value of an expression in the OLAP DML.
OLAP DML Function	OLAP DML Function	Returns the value of a function written in the OLAP DML.