In SAP BW (Business Warehouse), the concept ofHigh Cardinalityplays a crucial role in determining how data is stored and managed for InfoObjects. Let’s break down the scenario described in the question and analyze the effects on SID (Surrogate ID) values:
InfoObject: An InfoObject is a basic building block in SAP BW, representing a business entity like "ADDRESS" or "CITY".
High Cardinality Flag: When this flag is set for an InfoObject, it indicates that the InfoObject has a very large number of distinct values (high cardinality). This affects how SIDs are generated and managed.
SID (Surrogate ID): A unique identifier assigned to each distinct value of an InfoObject. SIDs are used to optimize query performance and reduce storage requirements.
InfoObject "ADDRESS": The High Cardinality flag is set for this InfoObject. This means that the system expects a large number of distinct values for "ADDRESS". As a result, SID generation for "ADDRESS" is deferred until actual data is loaded into the system. This approach avoids unnecessary overhead during activation and ensures efficient storage.
Attribute "CITY": This attribute does not have the High Cardinality flag set. Therefore, SIDs for "CITY" will be generated when the InfoObject is activated, as is typical for standard InfoObjects without high cardinality.
ForInfoObject "ADDRESS", since the High Cardinality flag is set,SID values are NOT generated during activation. Instead, they are generated dynamicallywhen data for "ADDRESS" is loadedinto the system. This behavior aligns with the design principle of high cardinality objects to defer SID generation until runtime.
Forattribute "CITY", SID values are generated during activation because it does not have the High Cardinality flag set.
Key Concepts:Scenario Analysis:Effects on SID Values:Why Option D is Correct:The correct answer isD. SID values are generated when data for InfoObject "ADDRESS" is loaded. This is consistent with the behavior of high cardinality InfoObjects in SAP BW. SID generation is deferred until data loading to optimize performance and storage.
[References:SAP BW Documentation on High Cardinality: SAP BW systems use the High Cardinality flag to manage large datasets efficiently. For high cardinality objects, SIDs are generated at runtime during data loading rather than during activation., SAP Note on SID Generation: SAP notes related to SID generation (e.g., Note 2008578) explain the behavior of high cardinality objects and their impact on SID management., SAP Data Fabric Best Practices: In scenarios involving high cardinality, deferring SID generation until data loading is recommended to ensure optimal performance and resource utilization., By understanding the implications of the High Cardinality flag and its interaction with attributes, we can confidently conclude that SID values for "ADDRESS" are generated only when data is loaded., ]
