Datawarehouse

Tue, 19 Aug 2008 13:29:19 +0200

What is Datawarehouse?

According to W.H.Inmon...A Datawarehouse is nothing but a
Subject-Oriented
Time-Variant
Non-Volatile
Integreted
storage of data.

Subject-Oriented: Subject-Oriented means it describes about a particular subject like Customer, Sales and Product.

Time-Variant: It means according to time data in datawarehouse changes beacause from time to time data will be loaded into the datawarehouse.

Non-Volatile: Once data is loaded into the datawarehouse it must not be deleted.

Integrated: i.e. data from different sources will be loaded and placed into one place(datawarehouse).

According to Ralph Kimbal, a datawarehouse is a copy of transactional data used for analysis purpose.

Schemas: There are different types of schemas are there for designing datawarehouse. They are
STAR SCHEMA
SNOW-FLAKE SCHEMA

Datawarehouse -- Business Objects