Infocubes are the central objects on which reports and analysis are based in SAP BW. It describes a self-contained data set within a business area, for which we can define queries.
Infocube consist of a central fact table and several surrounding dimension tables. As with other InfoCube types, the structure of a Basic InfoCube corresponds to the Star Schema. In SAP BW star schema , the facts in a fact table refers to key figure and the dimension attributes refer to characteristics.
In contrast to classic star schema concepts, characteristics are not component the dimension tables since the characteristic values are not stored in the dimension tables. They are stored in master data tables. There are foreign keys that replace the characteristics as the component of dimension table, i.e.: SID stand for Surrogate ID.
In summary
- InfoCubes are made up of a number of InfoObjects. All InfoObjects (characteristics and key figures) are available independent of the InfoCube. Characteristics refer to master data with their attributes and text descriptions.
- An InfoCube consists of several InfoObjects and is structured according to the star schema. This means there is a large fact table that contains the key figures for the InfoCube, as well as several dimension tables which surround it. The characteristics of the InfoCube are stored in these dimensions.
- The dimensions and the fact table are linked to one another using abstract identification numbers (dimension IDs) which are contained in the key part of the particular database table. As a result, the key figures of the InfoCube relate to the characteristics of the dimension. The characteristics determine the granularity at which the key figures are stored in the InfoCube.
- Characteristics that logically belong together are grouped together in a dimension. Dimensions are to a large extent independent of each other, and dimension tables remain small with regards to data volume. This is beneficial in terms of performance as it decouples the master data from any specific InfoCube. The master data can be used at a time by multiple InfoCubes. This InfoCube structure is optimized for data analysis.
- The fact table and dimension tables are both relational database tables.
- Characteristics refer to the master data with their attributes and text descriptions. All InfoObjects (characteristics with their master data as well as key figures) are available for all InfoCubes, unlike dimensions, which represent the specific organizational form of characteristics in one InfoCube.
- You can create aggregates to access data quickly. Here, the InfoCube data is stored redundantly and in an aggregated form.
- You can either use an InfoCube directly as an InfoProvider for analysis and reporting, or use it with other InfoProviders as the basis of a MultiProvider or InfoSet.
