Aggregation 

Use

To enable the calculation of key figures, the data from the InfoProvider has to be aggregated to the detail level of the query and formulas may also need to be calculated. The system has to aggregate using multiple characteristics. In regard to a selected characteristic, the system can aggregate with another rule for each key figure (exception aggregation).

Features

During aggregation, the OLAP Engine in BI proceeds as follows:

...

       1.      First, standard aggregation is executed. Possible aggregation types include summation (SUM), minimum (MIN) and maximum (MAX). Minimum and maximum can, for example, be used for date key figures.

       2.      Aggregation using a selected characteristic occurs after standard aggregation (exception aggregation). The available exception aggregation types include average, counter, first value, last value, minimum, maximum, no aggregation, standard deviation, summation, and variance. Application cases for exception aggregation include warehouse stock, for example, that cannot be totaled over time, or counters that count the number of characteristic values for a certain characteristic. See also: Examples in the Data Warehousing Workbench.

       3.      Lastly, aggregation using currencies and units is executed. A * is output when two numbers that are not equal to zero are aggregated with different currencies or units. See also: Currency Translation.

Formulas are calculated once the numbers have been completely aggregated. There are three exceptions to this rule:

●      For the key figure, a calculation time was selected in which the calculation of the formula is to be done before aggregation. See the section Tab Page Aggregation in Selection/Formula Properties.

●      When using a formula variable with replacement from an attribute value in a calculated key figure. See the section Tab Page Aggregation in Selection/Formula Properties.

●      During a currency translation that was set up in the Query Designer. See Currency Translation in the Business Explorer.

The sequence in which the values are calculated affects the result of the query. See also the example for the interpretation of query results.

The aggregation types are set during the definition of the key figure. See also: Tab Page: Aggregation. This section contains a detailed description of the aggregation types.

You can override the aggregation settings using settings in the query (in the Query Designer, BEx Web applications, and the BEx Analyzer). See also: Calculate Results As and Calculate Single Values As (local aggregation).

You can define the aggregation behavior for formulas and calculated key figures in the Query Designer. See also: Examples in the BEx Query Designer.