A staging area is an RDBMS database you create to meet the needs of specific applications. Typically, a staging area is small compared to a data warehouse or an online transaction processing (OLTP) application. As a snapshot of data, it is not constantly updated with new data but is refreshed periodically.
Use a staging area for these tasks:
Combine data from disparate or heterogeneous platforms without changing source data
Fine-tune data for an application
For example, you can calculate a subset of the data source data and then run faster queries on the precalculated data in the staging area.
Create tables or views to denormalize the data so that it maps more easily to an OLAP model (see Creating Views, Tables, and User-Defined Tables)
Transform data not consistently described (see Transforming Data)
Figure 3, Data Warehouse with Staging Area shows a staging area as part of a data warehouse. Data is copied into the staging area from the source data and then converted.
