Loading Architecture
Remember, there are two data loading architectures for fact tables: transform, then load and load, then transform (see Figure 7-1).
Figure 7-1. Common Data Warehouse ETL Architectures
The same data loading architecture options exist for loading aggregates; however, each of these scenarios becomes a bit more complex (Figures 7-2 and 7-3) as they add aggregation processes and aggregate tables to the flow. Plus, selecting an approach may limit your actual implementation options (e.g., does that approach work with materialized views?). You should review these options in detail and choose carefully.
Figure 7-2. “Transform Then ...
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