Fig. 8.3.3 The operational data store (ODS).

Data that flow to the ODS can flow directly into the ODS from the operational
environment, or data that pass to the ODS can pass through the ETL transformation
layer. Whether or not the data pass through, the ETL layer depends entirely on the class
of the ODS. In the case of a class I ODS, data pass directly from the operational system
to the ODS. In the case of a class II or class III ODS, data pass through the ETL
interface.

Not every corporation has or needs an ODS. Usually, it is those corporations where there
is a high degree of online transaction processing where the ODS is found.

The Staging Area

Chapter 8.3: The Data Warehouse/Operational Environment Interface