Database Reference
In-Depth Information
Figure 24-3.
Basic Data Warehouse
The data warehouse consists of raw data (from operational databases), summary
data and metadata. Summaries are very valuable in data warehouses because they
pre-compute long operations in advance. For example, a typical data warehouse query
may be to retrieve something like aggregate sales for a specific period. In Oracle, this may
be implemented as a materialized view or snapshot relation set up for that purpose.
24.4.2 Data Warehouse Architecture with a Staging Area
In the basic data warehouse, you need to clean and process your operational data before
putting it into the warehouse. You can do this programmatically, although most data
warehouses use a staging area instead. A staging area simplifies building summaries and
general warehouse management. Figure
24-4
illustrates this typical architecture.
