IS DATA WAREHOUSING IMPORTANT

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IS DATA WAREHOUSING IMPORTANT?

• Ghislaine NDEUTCHI, MICS Semester 1

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Outline

• The Context
• What is the problem?
• What is Data warehousing?
• Technologies used in a Data Warehousing project
• Advantages of Data Warehouse
• Concerns in using Data Warehouse
• Conclusion
• Is Data Warehousing necessary?

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The context (1)

• The success of a Company depends on its
  capability to understand its external and
  internal environments

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External environment
The context (2)

• A company must
• be able to integrate emergent markets
• be able to measure their strengths and their
  weaknesses
• Obtain decisional information related to future
  challenges

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Internal environment
The context (3)

• Structure of companies are generally
  decentralized to become closed to the markets
• ?we could find different databases for
  each function inside a company (Systems of
  production)

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What is the problem? (1)

• Business decision makers need information for
  fast and effective decision-makings
• Example what are the sales of a product in a
  town during the last 2 years?

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What is the problem? (2)

• How to reach to strategic information?
• How to analyse and manipulate all those
  quantities of separated data?
• Data Warehouse?

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What is Data Warehousing? (1)

• The term Data Warehouse was coined by Bill
  Inmon in 1990. His definition was the following
• "A warehouse is a subject-oriented,
  integrated, time-variant and non-volatile
  collection of data in support of management's
  decision making process".

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What is Data Warehousing? (2)

• Subject Oriented
• Integrated
• Time-Variant
• Non-volatile

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What is Data Warehousing? (3)
Illustration Typical Data Warehousing
environment
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What is Data Warehousing?(4)

• Data warehousing is essentially what we need
  to do in order to create a data warehouse, and
  what we do with it.
• It is the process that can involve a number
  of discrete technologies.
• ?

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Technologies used in a Data Warehouse Project (1)

• Source system identification localization of
  appropriate data (OLTP and historical data)
• Data warehouse design and creation !Ensure
  that the design supports the types of queries the
  warehouse will be used for
• Data acquisition It is the process of moving
  data from their sources into the warehouse.
  Performed by software products know as ETL
  (Extract/Transform/load)

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Technologies used in a Data Warehouse Project (2)

• Change data capture Periodic update of
  warehouse. (with replications server, triggers
  and store procedure)
• Data cleansing/scrubbing process that validate
  and if necessary correct the data before their
  insertion in the warehouse. (ETL)
• Data aggregation Summarise the data to store.
  (ETL)

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Technologies used in a Data Warehouse Project (3)

• When data warehouse have been built, it
  becomes possible to extract meaningful
  information from it that will provide a
  competitive advantage and a return on investment.
  Some tools to extract information are
• Multidimensional analysis tools (using OLAP)
• Query tools
• Data mining tools
• Data visualization tools

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Advantages of Data Warehouse (1)

• Enhances end-user access to a wide variety of
  data.
• Multidimensional visualization of data
• Business decision makers can obtain various kinds
  of trend reports. This may be helpful for future
  investments

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Advantages of Data Warehouse (2)

• Increases data consistency
• Increases productivity and decreases computing
  costs.
• Combine data from different sources, in one place
• Capability to replicate the changed data back
  into the operational systems

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Concerns in using data warehouse

• Extracting, cleaning and loading data could be
  time consuming
• Security must be taking in account
• Providing training to end-users

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Conclusion

• Data Warehousing is a complex field which
  require various tools,
• It has potential for enormous returns on
  investment,
• It is useful to take effective decisions.

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Question Is Data Warehousing necessary?

• Answer Yes, Data Warehousing is necessary as
  support of management's decision making process.
• But, According to the definition given by Inmon,
  it depends on the context.
• ? Views the next table

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• Questions