Sap Bw Query Requirements - IBM Cognos User Manual

SAP BW Query Requirements

For the remainder of this section, we assume that an SAP BW query is being used
as the basis for externalizing the data, not as the basis for reporting, and not with
the intent of exceeding the memory and time limitations associated with extracting
data directly from an InfoCube.
It is not possible to externalize an arbitrary SAP BW query. An SAP BW query
must adhere to the following restrictions if you want to externalize it:
v Set the characteristic display to Key. Setting the display to anything else may
result in incorrect data.
To change what appears for a characteristic, right-click the characteristic and
click Properties. In the Properties of Characteristic dialog box, change the
Display As value to Key.
We strongly recommend that you use Key.
v To reduce data volumes, as well as the amount of aggregation performed by the
SAP BW server, we strongly recommend that summarization for all
characteristics in the query be disabled in its property sheet.
To disable summarization for a characteristic, right-click the characteristic along
the edge of the SAP BW query and click Properties. In the Properties dialog
box, set the Suppress Results Rows value to Always.
v If at least one characteristic in an SAP BW query is displayed as something other
than Key, then summarization for all characteristics must be suppressed.
v The query must not contain the Currency/Unit characteristic.
v None of the characteristics may be assigned a display hierarchy, either explicitly
or by a variable.
v If a characteristic is included in an SAP BW query as a free characteristic, no
values will appear for that characteristic in the key figures extract.
A filter on a free characteristic acts as a filter on the data returned by SAP BW. It
is an efficient mechanism for defining a subset of an InfoCube.
Such a filter may also be applied to a characteristic along an axis of an SAP BW
query, in which case the filtered values appear in the key figures extract.
v All key figures in the SAP BW query must be numeric.
v The values of each key figure should be in a single currency. A variable should
not be used to drive the assignment of a target currency.
v Include in the SAP BW query only those characteristics which are to be extracted
using Framework Manager. Including unnecessary characteristics increases the
volume of data transferred from SAP BW, thus affecting performance.
Guidelines and Constraints When Working with SAP BW Cubes
You must use CSV files when importing metadata from SAP BW cubes. For
performance reasons, we recommend that you filter on geography, time periods, or
some other dimension that limits the amount of data retrieved. Remember to apply
your dimension filter to the related dimensions and their fact tables (measures).
For more information, see "Create a Filter" in the Framework Manager User Guide.
Because SAP BW cubes are multidimensional, rollups are applied at the source. If
you change the rollup type after importing the data into Cognos Transformer, your
results will not be valid.
Missing data or metadata that is out-of-scope for a particular measure may yield
different results, depending on the context. You may see:
Appendix E. Guidelines for Working with SAP BW Data for Use in Transformer
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