Data Warehouse Definition

Data Warehouse Definition

Different people has Different definitions for a data warehouse. The most popular definition came by Bill Inmon, who provided the following:

A data Warehouse is a subject-oriented (theme-oriented), integrated (integrated), time-variant (over time) and Non-volatile (Stable) collection of Da TA in support of management ' s decision making process.

subject-oriented: A data Warehouse can is used to analyze A particular Subject area. For example, the "sales" can be a particular subject.

Integrated: A Data Warehouse integrates data from multiple data sources. For example, source A and source B could have different ways of identifying a product, but in A data Warehouse, there would B E only a single-to identifying a product.

time-variant: Historical data is kept in a data warehouse. For example, one can retrieve data from 3 months, 6 months, and months, or even older data from a data warehouse. This contrasts with a transactions system, where often only the most recent data is kept. For example, a transaction system could hold the most recent address of a customer, where a data warehouse can hold all addr Esses associated with a customer.

non-volatile: Once data is in the Data Warehouse, it won't change. So, the historical data in a data warehouse should never is altered.

Ralph Kimball provided a more concise definition of a data warehouse:

A data warehouse is a copy of the transaction data specifically structured for query and analysis.

This is a functional view of a data warehouse. Kimball did not address how the data warehouse was built like Inmon did; Rather he focused on the functionality of a data warehouse.

Data Warehouse Definition