The purpose of the Data Warehouse in the overall Data Warehousing
Architecture is to integrate corporate data. It contains the "single
version of truth" for the organization that has been carefully constructed
from data stored in disparate internal and external operational databases.
The amount of data in the Data Warehouse is massive. Data is stored
at a very granular level of detail. For example, every "sale" that has
ever occurred in the organization is recorded and related to dimensions of
interest. This allows data to be sliced and diced, summed and grouped
in unimaginable ways.
Typical Data Warehousing
Environment
Contrary to popular opinion, the Data Warehouses does not contain all the
data in the organization. It's purpose is to provide key business
metrics that are needed by the organization for strategic and tactical
decision making.
Decision makers don't access the Data Warehouse directly. This is
done through various front-end Data Warehouse Tools that read data from
subject specific Data Marts.
The Data Warehouse can be either "relational" or "dimensional".
This depends on how the business intends to use the information.
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