Data Warehouse Definition

Data Warehouse Definition

What is a data warehouse?

A warehouse is a subject-oriented, integrated, time-variant and non-volatile collection of data in support of management's decision making process as first defined by Bill Inmon in 1990.

So what do these fancy terms mean in the above definition:

  • Subject-oriented - Data that gives information about a particular subject or topic or entity e.g. Customer,

    Supplier, Location.

  • Integrated - Data that is gathered from a variety of sources and merged into a consistent whole.
  • Time-Variant - Data is identified with a particular time period.
  • Non-Volatile - Data is added but data is never removed. This enables management to gain a consistent picture of the business over the time period of interest.
In simpler words,

It is a database designed to support decision making in an organization. Data from the production databases ( e.g. Order processing ) is selectively copied to the data warehouse so that queries can be performed without disturbing the performance or the stability of the production systems.

Data warehouses can become enormous with hundreds of gigabytes of transactions. As a result, subsets, known as "data marts" are often created for just one department, product line,or subject e.g. Customers.

Go to Top of Data Warehouse Definition page

Return to Data Warehouse Basics

Return to What is Business Intelligence?