Request
Enhance Semantic Modeler to support logical hierarchies whose levels and attributes are sourced from more than one logical dimension table, including existing enterprise modelling patterns in which:
- dimension attributes are provided through a dimension structure backed by a
_D table; and - hierarchy information is maintained separately, for example in an Oracle BI Applications
_DH hierarchy table.
The resulting logical tables should be usable within the same logical dimension/hierarchy without requiring them to be consolidated into a single logical table solely for Semantic Modeler compatibility.
Rationale
Semantic Modeler currently requires a hierarchy (logical dimension) to be based on a single logical dimension table. Oracle's migration guidance therefore requires existing RPD models whose hierarchies span multiple logical tables to be remodelled and the logical tables consolidated before migration.
This restriction creates a migration issue for existing, valid RPD-based models that use separate structures to represent dimension attributes and hierarchical relationships.
The issue is particularly relevant to Oracle BI Applications. Oracle Business Analytics Warehouse defines _D tables for dimension data and separate _DH tables for dimension hierarchy structures. Oracle documents _DH tables specifically as storing the hierarchical structure associated with dimensions. Existing OBIA semantic models can therefore use modelling patterns that do not conform to Semantic Modeler's single-logical-table requirement.
The enhancement is not intended to be OBIA-specific. It would enable migration and continued use of existing RPD models where a logical hierarchy legitimately depends on columns represented in multiple logical dimension tables.
Business Benefits
- Improve compatibility between Semantic Modeler and existing RPD-based semantic models.
- Reduce manual redesign required when migrating models to Semantic Modeler.
- Preserve Oracle-delivered OBIA modelling patterns where applicable.
- Avoid consolidation of logical structures solely to satisfy a Semantic Modeler migration constraint.
- Reduce migration complexity, effort, and regression risk for enterprise semantic models.
- Increase adoption of Semantic Modeler for complex existing Oracle Analytics implementations.
Expected Outcome
Semantic Modeler should support a logical hierarchy whose levels, keys, and attributes reference columns from more than one logical dimension table.
This capability should fully support hierarchy navigation, level keys, level-based measures, validation, query generation, and RPD migration.
This enhancement would remove a documented migration limitation and improve compatibility with existing enterprise semantic models, including Oracle BI Applications implementations.
Reference SR: 4-0002390687 — OBIA 10.3: Issue with Semantic Modeler
