Data warehouse is a Subject oriented, Integrated, Time variant, Non volatile
collection of data in
support of management's decision making process.
Subject Oriented
Data warehouses
are designed to help you analyze data. For example, to learn more about your company's sales data,
you can build a warehouse that concentrates on sales. Using this warehouse, you
can answer questions like "Who was our best customer for this item last
year?" This ability to define a data warehouse by subject matter, sales in
this case makes the data warehouse subject oriented.
Integration is
closely related to subject orientation. Data warehouses must put data
from disparate sources into a consistent format. They must resolve
such problems as naming conflicts and inconsistencies among units of measure.
When they achieve this, they are said to be integrated.
Nonvolatile
means that, once entered into the warehouse, data should not change. This is logical because the purpose of a
warehouse is to enable you to analyze what has occurred.
In order to
discover trends in business, analysts need large amounts of data. This is very much in contrast to online transaction processing (OLTP) systems,
where performance requirements demand that historical data be moved to an
archive. A data warehouse's focus on change over time is what is meant by the
term time variant.
No comments:
Post a Comment
Thank you :
- kareem