A data ware house is a
combination of data and warehouse in which data represent in the Facts and the
Dimensions. It is nothing but a storage place for data and used to store
current and historical information. We are storing the data in data ware house
from heterogeneous data sources. It is
different from traditional database in terms of size volume and space along
with content. Due to the size and nature of data ware house, we are maintained
separately from database.
According to Ralph
Kimball : “
Data ware house is the conglomerate of all data marts within the enterprise.
Information is always stored in the dimensional model.”
According to Billnmon : “A ware house is a subject - oriented, Integrated, time-variant and non-volatile collection of data in support of Management decision making process.”
Properties of data
ware house
Subject oriented: Any particular subject can be analyzed using
a data ware house. The subject depends on which organizational the data ware
house.
Time variant: A major advantage of data ware house over traditional
database that it keeps track of historical data.
Integrated: Data ware house are repositories made by integrating
data, information and knowledge from the heterogeneous database.
Non- volatile: As data ware house contain the historical data any
alternation or changes are not possible.
Use of Data ware house
Ø A single point of access for all data, rather than requiring users to connect to dozen or even hundreds of the system individually.
Ø Enhancing the time for analysis and reporting.
Ø Improved business intelligence.
Ø Benefit of historical data.
Ø Standardization of data.
Ø Data mining.
Ø Metadata ability.
Ø Making Decision support system(DSS)
Ø Store the historical data.
