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What is Data Warehousing ?
Data warehousing combines data from
multiple and usually varied sources. It can be any number of
heterogeneous sources as long as the system can handle that
mass. It eventually makes a homogeneous database out of this and
the end result is a comprehensive and easily manipulated
database.
How does data warehousing operate ?
Data warehousing operates through assessing systems like
queries, analysis and reporting.
What are the features of a data
warehouse ?
A data warehouse is a repository which includes integrated
information which is available for queries and analysis. A data
warehouse is:
• Subject oriented- This means that the data in the data
warehouse is arranged based on the same real world event or
object.
• Time variant- The changes to the data in the data warehouse
can be tracked and recorded. This will help generate reports
which show the changes according to time-variance.
• Non volatile- The data in the data warehouse is static and
read only because it is retained for future predictions. It is
never over written or deleted. |
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• Integrated- The data in the data
warehouse has an integrated data form all the operational
applications of the organization.
Why data
warehousing ?
Data warehousing helps in extracting and storing informational
data which makes it easier for business analysts to predict
future sales of product in the market. The systems that contain
operational data which runs the daily transactions of business
is a useful repository for business analysts. However, if the
operational data is analyzed directly, several problems are
bound to arise. It requires expertise to analyze the operational
database as it uses a specialized type of data manipulation
language. The system will not be able to handle users who make
adhoc queries. The operational data available may not be in a
conducive format for use. |
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Data warehousing attempts to solve
these problems. It has tools which will extract stores of
informational data from the operational data by copying files
and data from the operational database. It then performs
calculations to summarize the data and then writes it to a
database which is separated from the operational data. This
separated database or warehouse will enable users to query and
analyze the information without having to go to the operational
database.
Uses of data warehousing
Data warehousing helps companies to view daily operations as
well as long term data overviews. This enables companies to
analyze market trends. It also results in productive strategic
planning, evolving business models and forecasts and preparing
reports and projections. However the data stored in the data
warehousing has to be updated when a new query arises.
In data warehousing, smaller amounts of data are grouped into
data marts. This gives users the access to use both data
warehousing and data marts form which they can choose the source
and functionality depending on current needs.
Limitations of data warehousing
Data warehousing is definitely not the end solution for
analyzing a company’s data. However, it has useful analysis for
specific data. Then companies will have to resort to more
comprehensive data storage which are more static and less easily
manipulated than data warehousing. Data warehousing typically
suits big companies. Smaller companies use datamarts if they
wish to analyze only one subject which has a more specific
storage and reporting.
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Article Contributed By: Sabina
Zacharias
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