Aggregation 

Use

To calculate the value of key figures, the data from the InfoProvider has to be aggregated at the detail level for the query. It is possible that formulas also have to be calculated.  In this case, several characteristics have to be aggregated. For each key figure, one selected characteristic can be aggregated with another rule.

Features

The OLAP engine in the BW proceeds as follows:

...

       1.      Standard aggregation is executed first. Possible types if aggregation are summation (SUM), minimum (MIN), and maximum (MAX). Minimum and maximum can be set, for example, for date key figures.

       2.      The aggregation of a selected characteristic takes place after the standard aggregation (exception aggregation). Possible exception aggregations available are average, counter, first value, last value, minimum, maximum, no aggregation, standard deviation, summation and variance. Cases where exception aggregation would be applied include, for example, storage non-cumulatives that can not be totaled by time, or counters that count the number of characteristics for a particular characteristic.  For more information, see the examples Scenarios for the Use of Exception Aggregation.

       3.      Aggregation by currency and units is executed last.  If two figures are aggregated unequally with different currencies or units, the system marks this with ‘*’. See also Currency Translation.

Formulas are only calculated after figures have been fully aggregated. There are three exceptions to this rule:

·        When the time for calculating the key figure has been selected so that the calculation of the formula is to take place before aggregation. See also the section on aggregation behavior in Properties of the Calculated Key Figure.

·        When a formula variable is used with replacement from the value of an attribute in a calculated key figure. See also the section on aggregation behavior in Properties of the Calculated Key Figure.

·        With a currency translation that was set in the query designer. See also Currency Translation in the Business Explorer

The sequence in which the values are calculated affects the result in the query. See also the example on Interpretation of Query Results.

These aggregation types can be set in the key figure definition. See also Tab Page: Aggregation. In this section you will also find a detailed description of the types of aggregation.

You can also override these settings by making settings in the query. See also:

·        In the Query Designer: Properties of the Calculated Key Figure

·        In the Query Designer, in BEx Web Applications and in the BEx Analyzer: Calculate Result As... and Calculate Single Values As... (local aggregation)