Objects in BW can be modeled with InfoObjects or with fields. Modeling InfoObjects brings additional effort, but offers a number of advantages. When deciding whether to model with fields or with InfoObjects, you should consider how much of the flexibility that the fields offer you you need, and which functions or performance that the InfoObjects offer you you can do without.
You should model central master data objects (navigation attributes and hierarchies) using persistent InfoObjects. With many OLAP functions, this offers you advantages in terms of performance.
In the entry layer in the data warehouse however, where there is little need for OLAP functions, and smaller data volumes are processed, using fields can enhance the flexibility and range of the data warehouse.
Functional restrictions when modeling with fields
- The services for InfoObjects (attributes and hierarchies for example) are not available for fields.
- Fields are displayed in the CompositeProvider / the query with the generated name 4<InfoProvider>-<field name>.
- Validity characteristics for DataStore objects (advanced) with non-cumulative key figures must be InfoObjects.
- InfoObject attributes must be InfoObjects.
- A field-based key figure cannot be an exception aggregation.
- An association with an Open ODS view is only possible once for navigation attributes.
- Planning queries on DataStore objects (advanced) are only supported with fields as read-only.
Performance when modeling with fields
- If the query contains fields, it can be processed key-based in SAP HANA.
- If an open ODS view contains compounded fields, processing in SAP HANA is not possible.
- If fields are used in the query definition, the OLAP cache cannot be used.
- If fields from open ODS view and InfoObjects are used as navigation attributes based on a SAP HANA view in CompositeProviders, performance will be impaired when processing the query filter on them in SAP HANA. More information: 2103032
- In the query on a CompositeProvider, not all data types for fields are supported:
More information: 2185212
- The maximum length for fields is 20 characters.
- Not all characters are supported.
- If fields are used in the query, the InfoProviders can only be read sequentially.