Oracle^® Business Intelligence Applications Installation and Configuration Guide > Customizing the Oracle Business Analytics Warehouse > Type I Customizations: Adding Columns to Existing Fact or Dimension Tables >

About Extending Mappings

Type I customizations involve extracting additional columns from source systems that are already mapped (for example, Siebel or Oracle) and loading the data into existing data warehouse tables. For Type I customizations, data can also come from non-packaged sources, but this section assumes that the sources have already been mapped with a Universal adaptor and only need to be extended to capture additional columns. (The initial mapping of a Universal adaptor is considered a Type III customization. For information, see Type III Customizations: Adding New Data as a Whole Row into a Standard Dimension Table.)

In order to see additional columns in the data warehouse, the columns must first be passed through the ETL process. The existing mappings and tables are extensible. Sample placeholders demonstrate how to pass and store additional data. Oracle BI Applications provides a methodology to extend preconfigured mappings to include these additional columns and load the data into existing tables.

Oracle BI Applications recognizes two types of customization: extension and modification. The supported extension logic allows you to add to existing objects. For example, you can extract additional columns from a source, pass them through existing mappings, and populate new columns added to an existing table. Generally, Oracle BI Applications does not allow you to modify existing logic or columns. You should not change existing calculations to use different columns, and you should not remap existing columns to be loaded from different sources.

For example, if you want to calculate revenue differently from the existing logic, you should create a new transformation and connect that calculation to a new column, for example, X_REVENUE. You can then remap the Oracle Business Intelligence repository to point to the new X_REVENUE column.

Most mappings have a single placeholder column, named X_CUSTOM, that marks a safe path through the mapping. All extension logic should follow the same route through the mapping as X_CUSTOM. You can add additional transformations to the mapping, but they should follow the same route through the mapping as X_CUSTOM.

In Figure 6 the preconfigured logic is shaded in gray. You should not modify anything contained within these objects. You should add customizations to the existing mapping, which allows them to run parallel to the existing logic.

Figure 6. Type I Customization

Because some objects need to be modified in order to allow for extensions, Oracle BI Applications breaks down extensions into two categories:

• Exposed objects. These objects allow changes, but the changes must be in the form of extensions (additive), and must never modify existing preconfigured logic. These objects are included in the mapping when shipped and are usually sources, targets, and nonreusable transformations.
• Encapsulated objects. These objects cannot be extended. They attempt to hide as much of the shipped transformation logic as possible to prevent breaking the preconfigured logic. They should never be changed in any way unless directed by Oracle. These objects are included in the mapping when shipped and are usually mapplets and reusable transformations.
• Custom objects. You add custom objects to a mapping. (They are not shipped by Oracle.) Custom objects can be sources, transformations (reusable and nonreusable), or mapplets. Reusable transformations and mapplets that are shipped are considered encapsulated objects, but when you add such objects to an existing mapping, they are considered custom objects to that particular mapping. For example, if you want to add another amount to a fact table and that amount needs to be converted from its original currency to the data warehouse currency, you would normally add the existing Currency Exchange mapplet to the mapping to convert this new amount. In this case, the mapplet is considered a custom object to this particular mapping; however, it is also encapsulated, so the internal logic must not be changed.

  NOTE:  Targets should not be added to a mapping.