èThe various structures provided for creating a Data Model in SAP BW are:
l
1.InfoObjects
2.lInfoCube
3.lODS (Operational DataStore)
4.lMultiProvider
5.lInfoSet
1.InfoObjects
1.InfoObjects
è Business evaluation objects are known in BW as InfoObjects. They are the basic information providers of BW and the smallest information units in BW.
è They structure the information needed to create InfoCubes/ODS Objects.
èInfoObject types:
l Characteristics
l Basic
l Time
l Technical
l Key figures
è Characteristics InfoObjects are business reference objects which are used to analyze key figures such as company code, material, product, customer group.
è Key Figures InfoObjects provide values to be evaluated such as quantity, amount, or number of items.
è Time characteristics are characteristics such as date, fiscal year which are time indicators.
è Units Characteristic are required so that the values for the key figures have meanings. Key figures of type amount are always assigned a currency key and key figures of type quantity also receive a unit of measurement.
è Technical characteristics are used for administrative purposes only within BW. An example of a technical characteristic is the request number in the InfoCube. This is generated when you load a request as an ID and helps locate the request at a later date.
Master Data – Attributes, Texts & Hierarchy
è Characteristics bear master data (i.e. attributes, texts or hierarchies) in BW.
è ‘Attributes’ are InfoObjects that are logically subordinate to a characteristic.
èTypes of Master Data attributes
l Display Attribute – Used for display purpose in report and cannot be used for drill-down and filtering purpose. (for e.g. Material weight or Material colour)
l Navigational Attribute – Navigational attribute can be used for further analysis in reporting (e.g. Material group, Material class)
è The description of the characteristic is stored as InfoObject ‘text’.
l e.g. Material # 1000023456 has a description viz. "Metallic Black Part 1L”.
èA ‘hierarchy’ forms a summarization and grouping for a characteristic according to individual evaluation criteria.
l e.g. Material can have the 4 levels of hierarchy as Product Category -> Product class-> Material group-> Material. These levels can be used in reporting for further drill down in data
InfoObject Catalog
è An InfoObject catalog is a collection of InfoObjects grouped according to application-specific criteria
è
Types of InfoObject catalog
l Characteristic: This is the collection of Characteristics InfoObjects
l Key figure: This is the collection of Key figures InfoObjects
InfoCube
è InfoCubes are central objects of multi-dimensional model in SAP BW. Reports and analysis are based on InfoCubes.
è An InfoCube describes an self-enclosed dataset for business-area from a reporting point of view.
è An InfoCube consists of several InfoObjects and is structured according to the star schema.
è An InfoCube is additive in nature, it aggregates data on the basis of characteristics combinations.
èTypes of InfoCubes
l Basic
l Basic InfoCube
l Transactional InfoCube
l Virtual InfoCube
l Remote Cube
l SAP Remote Cube
l Virtual InfoCube with Services
è
The characteristics determine the granularity (the degree of detail) at which the key figures are kept in the InfoCube.
è Characteristics that logically belong together (district and area, for example, belong to the regional dimension) are grouped together in a dimension.
è An InfoCube can have maximum of 16 dimensions (3 dimensions are provided by SAP)
i.e. Time, Data Package and Unit). A maximum of 256 characteristics can be included in each dimension.
è Dimension tables should be small with regards to data volume, which is desirable for reasons of performance.
Transactional InfoCube
è A transactional InfoCube is a special Basic InfoCube, especially developed for SAP SEM.
è The system accesses data in such a InfoCube is transactional, in other words, data is written to the InfoCube and instantly read again when required.
l e.g. In BW BPS, users enter plan data via planning layouts which is in turn stored in Transactional InfoCubes.
è A standard Basic InfoCube is optimized for pure read access and hence not suitable here.
Virtual InfoCube
Virtual InfoCubes are special InfoCubes. A virtual InfoCube represents a logical view. Unlike Basic InfoCube, no data is physically stored in BW. The data is taken from the source system only after a query has been executed.
è SAP Remote Cube allows one to define queries with direct access to transaction data in other SAP systems.
è Remote Cube allows reporting using data from non-SAP systems. the external system transfers the requested data to the OLAP processor via the BAPI.
è Virtual InfoCube with Services requires a user-defined function module as a DataSource.
ODS
• An ODS object (Operational DataStore) acts as a storage location for consolidated and cleaned-up transaction data (transaction data or master data, for example) on the document (atomic) level.
• An ODS object contains key fields (for example, document number/item) and data fields that can also contain character fields (for example, order status, customer) and key figures.
•Types of ODS Object
l Basic ODS
l Transactional ODS
èEvery ODS object is represented on the database by three transparent tables:
l Active data: A table containing current status of data
l Activation queue: New data is saved in this table before it is activated. The data in this table is deleted after activation.
l Change log: Contains the complete (activation) history of the changes to ODS data
Transactional ODS
è A transactional ODS object differs from a standard ODS object in the way it prepares data.
èIn a standard ODS object, data is stored in different versions (active, delta, modified), whereas a transactional ODS object contains the data in a single version. Therefore, data is stored in precisely the same form in which it was written to the transactional ODS object by the application.
è The transactional ODS object is also required by diverse application such as SAP SEM.
èTransactional ODS objects allow data to be available quickly. The data from this kind of ODS object is accessed transactionally and read again, as soon as possible.
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