Data warehouse Layer

There is no widespread agreement on exactly what constitutes a data warehouse architecture. Though they may not be contradictory, views differ as to the relative importance of the possible components. One possible conceptualization of a data warehouse architecture consists of the following interconnected layers:

Operational database layer

The source data for the data warehouse

Informational access layer

The data accessed for reporting and analyzing and the tools for reporting and analyzing data

Data access layer

The interface between the operational and informational access layer

Metadata layer

The data directory (which is often much more detailed than an operational system data directory).