This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
SAP BW Data Modeling
SAP University AlliancesVersion 2.0Authors Klaus Freyburger g
Peter Lehmann
Abstract:This chapter covers the basic aspects and concepts of data modeling with SAP Business Information Warehouse (SAP BW).
• A Characteristic represents a business object (or concept• A Characteristic represents a business object (or concept, business term, business entity).– A Characteristic may have attributes which describes the
b i bj i d ilbusiness object in more detail.– Example: InfoObject “Customer” is a characteristic with
attributes such as “Customer Number”, “ZIP Code”, “Region”, , , g ,etc.
– The attributes “Customer Number”, “ZIP Code”, “Region”, etc. are also managed as Characteristics and may have their ownare also managed as Characteristics and may have their own attributes.
Note: What SAP calls a Characteristic is often referred to in the data warehouse community as a Dimension.
• A Key Figure (or variable measure) is oftenly used to document• A Key Figure (or variable, measure) is oftenly used to document the performance of a business process over time.– It can be found in document records such as invoice, delivery
h d d inote, purchase order, or goods receipt.– Example: InfoObject “Revenue” or “Sales Amount”, etc.
• Note: InfoObjects are unique inside SAP BW, and they are used to build the data structures for analysis requirements.– Conceptually unique: the semantics (meaning) of an
InfoObject is uniquely defined system-wide inside SAP BW.– Logically unique: the data type value range or field length isLogically unique: the data type, value range or field length is
uniquely defined system-wide inside SAP BW.– From the technical point of view, an InfoObject can viewed as a
I f P id “P id ” A t D t R dBI2-M2 SAP BW Data Modeling
InfoProviders “Provide” Access to Data Records
InfoProviders:InfoProviders:• Are data storage inside SAP BW• May store data records physically (persistent)• May also be used to access data stored outside SAP BW virtually
(transparent views)• May be accessed with front end tools such as SAP• May be accessed with front end tools such as SAP
BusinessExplorer
Note: A query is a “view” to data within an InfoProvider and does not contain physical dataand does not contain physical data.
6-8 dimensions (+ the 3 above) so 13 dimensions are plenty.
SAP BI Curriculum
SAP UA
D t St Obj tBI2-M2 SAP BW Data Modeling
DataStore Objects
• Contain single data records such as invoices, g ,purchase orders or customer order items.
• Consist of key fields (such as “order number”, “order position number”) and data fields (Key Figures andorder position number ) and data fields (Key Figures and Characteristics such as “sales amount”, “ net value”, “customer id”, “material number”).
• Store data records in relational database tables.• Often contain massive volumes of data.
If the Key Figure is non-cumulative (e.g., warehouse stock), this field defines an InfoObject representing non-cumulative change. This InfoObject is either positive or negative. So, the stock amount can be calculated f itfrom it. Two fields are used to
calculate the non-cumulative amounts. Inflow is the InfoObject which represents the stock inflow amount. Outflow is
Alphanumeric database fieldsAlphanumeric database fields• Datatype CHAR in SAP• Can store character and number values• Have conversion exit ALPHA as default
– Eliminates leading blanks after user input• User input of ‚RB0010‘ and ‚ RB0010‘ refers to same objectp j
– Stores numbers with leading 0s in database• Numeric values are stored in natural order in database, e.g. 0002
first then 0010first, then 0010
Material Group in SAP Business Content has numerical l ith t ili bl kvalues with trailing blanks
Database field Material often requires special treatmentDatabase field Material often requires special treatment.• Datatype CHAR in SAP• Conversion exit MATN1 is used• Edit format can be defined in transaction OMSL
– E.g. _ _-_ _ _ _ User Input RB-0010 is stored as RB0010
Since the OMSL format setting is system-wide, we do not use it in the Bike Company Curriculum.
• Time characteristics are always• Time characteristics are always necessary and define the time-related reference point for data analysis purposesanalysis purposes.
• Time characteristics are predefined by SAP and cannot be changed.
• Units and Currencies are used to define Key Figures in more detail• Units and Currencies are used to define Key Figures in more detail.• A Unit may be an InfoObject which defines the Unit of a Key Figure.• A Currency may be an InfoObject which defines the Currency of a
Ch i I f Obj t t B ild D t St Obj tBI2-M2 SAP BW Data Modeling
Choosing InfoObjects to Build a DataStore Object
• Select the relevant InfoObjects• Select the relevant InfoObjects– Direct InfoObject name input (1) or– Choose InfoObjects by InfoObjectCatalog and drag & drop the
7 Steps to Define an InfoCube7 Steps to Define an InfoCube1) Choose a name for an InfoCube2) Create Dimensions as needed3) Assign Characteristics to Dimensions4) Choose Time Characteristics5) Choose Key Figures5) C oose ey gu es6) Define Navigational Attributes7) Activate InfoCube
Wh t i Di i I id SAP BW?BI2-M2 SAP BW Data Modeling
What is a Dimension Inside SAP BW?
• A dimension is a group of characteristics which belong to the• A dimension is a group of characteristics which belong to the same business object (semantically).
• Each characteristic may contain additional attributes which are l f d l i !!!relevant for data analysis – or not!!!
Navigational attributes are InfoObjects which are used to perform data analysis.Display attributes are InfoObjects for which data analysis does
not make sense (e.g. a house number or a family name)This has an impact to cube design!This has an impact to cube design!
Note: In data warehouse community, the term Dimension isNote: In data warehouse community, the term Dimension is used for what SAP calls Characteristic .
• Define the InfoObjects needed• Define the InfoObjects needed.– Key Figures– Characteristices
• Define which Characteristics may be chosen to create a semantic cluster for semantic dimensions.– Examples are: Sales, Production, Material Management, Finance, etc.Examples are: Sales, Production, Material Management, Finance, etc.
• Define which attributes are appropriate to perform data analysis– OLAP attributes define them as “navigational” attributes – Non-OLAP attributes define them as “display” attributes
• Key Figures and Characteristics are defined as InfoObjects• Key Figures and Characteristics are defined as InfoObjects.• InfoObjects are the smallest “bricks” to define InfoProviders
within SAP BW.• InfoProviders are used to store data within SAP BW or allow SAP
BW to access data stored somewhere else.• The most important InfoProviders are InfoCubesThe most important InfoProviders are InfoCubes
and DataStore Objects.• The definition of an SAP BW InfoCube is